Phenylalanine derivatives

ABSTRACT

Phenylalanine derivatives of formula (1) are described:                    
     in which: 
     Ar 1  is an aromatic or heteroaromatic group; 
     L 1  is a linker atom or group; 
     R is a carboxylic acid or a derivative thereof; 
     Ar 2  is an optionally substituted aromatic or heteroaromatic group; 
     and the salts, solvates, hydrates and N-oxides thereof. 
     The compounds are able to inhibit the binding of α4 integrins to their ligands and are of use in the prophylaxis and treatment of immune or inflammatory disorders.

This invention relates to a series of phenylalanine derivatives, to compositions containing them, to processes for their preparation, and to their use in medicine.

Over the last few years it has become increasingly clear that the physical interaction of inflammatory leukocytes with each other and other cells of the body plays an important role in regulating immune and inflammatory responses [Springer, T A. Nature, 346, 425, (1990); Springer, T. A. Cell 76, 301, (1994)]. Many of these interactions are mediated by specific cell surface molecules collectively referred to as cell adhesion molecules.

The adhesion molecules have been sub-divided into different groups on the basis of their structure. One family of adhesion molecules which is believed to play a particularly important role in regulating immune and inflammatory responses is the integrin family. This family of cell surface glycoproteins has a typical non-covalently linked heterodimer structure. At least 14 different integrin alpha chains and 8 different integrin beta chains have been identified [Sonnenberg, A. Current Topics in Microbiology and Immunology, 184, 7, (1993)]. The members of the family are typically named according to their heterodimer composition although trivial nomenclature is widespread in this field. Thus the integrin termed α4β1 consists of the integrin alpha 4 chain associated with the integrin beta 1 chain, but is also widely referred to as Very Late Antigen 4 or VLA4. Not all of the potential pairings of integrin alpha and beta chains have yet been observed in nature and the integrin family has been subdivided into a number of subgroups based on the pairings that have been recognised [Sonnenberg, A. ibid].

The importance of cell adhesion molecules in human leukocyte function has been further highlighted by a genetic deficiency disease called Leukocyte Adhesion Deficiency (LAD) in which one of the families of leukocyte integrins is not expressed [Marlin, S. D. et al J. Exp. Med. 164, 855 (1986)]. Patients with this disease have a reduced ability to recruit leukocytes to inflammatory sites and suffer recurrent infections which in extreme cases may be fatal.

The potential to modify adhesion molecule function in such a way as to beneficially modulate immune and inflammatory responses has been extensively investigated in animal models using specific monoclonal antibodies that block various functions of these molecules [e.g. Issekutz, T. B. J. Immunol. 3394, (1992); Li, Z. et al Am. J. Physiol. 263, L723, (1992); Binns, R. M. et al J. Immunol. 157, 4094, (1996)]. A number of monoclonal antibodies which block adhesion molecule function are currently being investigated for their therapeutic potential in human disease.

One particular integrin subgroup of interest involves the α4 chain which can pair with two different beta chains β1 and β7 [Sonnenberg, A. ibid]. The α4β1 pairing occurs on many circulating leukocytes (for example lymphocytes, monocytes and eosinophils) although it is absent or only present at low levels on circulating neutrophils. α4β1 binds to an adhesion molecule (Vascular Cell Adhesion Molecule-1 also known as VCAM-1) frequently up-regulated on endothelial cells at sites of inflammation [Osborne, L. Cell, 62, 3, (1990)]. The molecule has also been shown to bind to at least three sites in the matrix molecule fibronectin [Humphries, M. J. et al. Ciba Foundation Symposium, 189, 177, (1995)]. Based on data obtained with monoclonal antibodies in animal models it is believed that the interaction between α4β1 and ligands on other cells and the extracellular matrix plays an important role in leukocyte migration and activation [Yednock, T. A. et al, Nature, 356, 63, (1992); Podolsky, D. K. et al. J. Clin. Invest. 92, 373, (1993); Abraham, W. M. et al. J. Clin. Invest. 93, 776, (1994)].

The integrin generated by the pairing of α4 and β7 has been termed LPAM-1 [Holzmann, B and Weissman, I. EMBO J. 8, 1735, (1989)] and like α4β1, binds to VCAM-1 and fibronectin. In addition, α4β7 binds to an adhesion molecule believed to be involved in the homing of leukocytes to mucosal tissue termed MAdCAM-1 [Berlin, C. et al, Cell, 74, 185, (1993)]. The interaction between α4β7 and MAdCAM-1 may also be important at sites of inflammation outside of mucosal tissue [Yang, X-D. et al, PNAS, 91, 12604 (1994)].

Regions of the peptide sequence recognised by α4β1 and α4β7 when they bind to their ligands have been identified. α4β1 seems to recognise LDV, IDA or REDV peptide sequences in fibronectin and a QIDSP sequence in VCAM-1 [Humphries, M. J. et al, ibid] whilst α4β7 recognises a LDT sequence in MAdCAM-1 [Briskin, M. J. et al, J. Immunol. 156, 719, (1996)]. There have been several reports of inhibitors of these interactions being designed from modifications of these short peptide sequences [Cardarelli, P. M. et al J. Biol. Chem. 269, 18668, (1994); Shroff, H. N. Bioorganic. Med. Chem. Lett. 6, 2495, (1996); Vanderslice, P. J. Immunol. 158, 1710, (1997)]. It has also been reported that a short peptide sequence derived from the α4β1 binding site in fibronectin can inhibit a contact hypersensitivity reaction in a trinitrochlorobenzene sensitised mouse [Ferguson, T. A. et al, PNAS 88, 8072, (1991)].

Since the alpha 4 subgroup of integrins are predominantly expressed on leukocytes their inhibition can be expected to be beneficial in a number of immune or inflammatory disease states. However, because of the ubiquitous distribution and wide range of functions performed by other members of the integrin family it is very important to be able to identify selective inhibitors of the alpha 4 subgroup.

We have now found a group of compounds which are potent and selective inhibitors of α4 integrins. Members of the group are able to inhibit α4 integrins such as α4β1 and/or α4β7 at concentrations at which they generally have no or minimal inhibitory action on α integrins of other subgroups. The compounds are thus of use in medicine, for example in the prophylaxis and treatment of immune or inflammatory disorders as described hereinafter.

Thus according to one aspect of the invention we provide a compound of formula (1)

wherein

Ar¹ is an aromatic or heteroaromatic group;

R¹, R², R³, R⁴ and R⁵ which may be the same or different is each an atom or group —L²(Alk³)_(t)L³(R⁷)_(u) in which L² and L³ which may be the same or different is each a covalent bond or a linker atom or group, t is zero or the integer 1, u is an integer 1, 2 or 3, Alk³ is an aliphatic or heteroaliphatic chain and R⁷ is a hydrogen or halogen atom or a group selected from alkyl, —OR⁸ [where R⁸ is a hydrogen atom or an optionally substituted alkyl group], —SR⁸, —NR⁸R⁹ [where R⁹ is as just defined for R⁸ and may be the same or different], —NO₂, —CN, —CO₂R⁸, —SO₃H, —SOR⁸, —SO₂R⁸, —OCO₂R₈, —CONR⁸R⁹, —OCONR⁸R⁹, —CSNR⁸R⁹, —COR⁸, —OCOR⁸, —N(R⁸)COR⁹, —N(R⁸)CSR⁹, —SO₂N(R⁸)(R⁹), —N(R⁸)SO₂R⁹, —N(R⁸)CON(R⁹)(R¹⁰), [where R¹⁰ is a hydrogen atom or an optionally substituted alkyl group] —N(R⁸)CSN(R⁹)(R¹⁰) or —N(R⁸)SO₂N(R⁹)(R10);

Alk¹ is an optionally substituted aliphatic or heteroaliphatic chain;

L¹ is a covalent bond or a linker atom or group;

Alk² is a straight or branched alkylene chain;

m is zero or an integer 1;

R⁶ is a hydrogen atom or a methyl group;

r is zero or the integer 1;

R is a carboxylic acid (—CO₂H) or a derivative thereof;

R^(a) is a hydrogen atom or a methyl group;

g is zero or the integer 1;

Ar² is an optionally substituted aromatic or heteroaromatic group;

and the salts, solvates, hydrates and N-oxides thereof.

It will be appreciated that compounds of formula (1) may have one or more chiral centres, and exist as enantiomers or diastereomers. The invention is to be understood to extend to all such enantiomers, diastereomers and mixtures thereof, including racemates. Formula (1) and the formulae hereinafter are intended to represent all individual isomers and mixtures thereof, unless stated or shown otherwise.

In the compounds of formula (1), derivatives of the carboxylic acid group R include carboxylic acid esters and amides. Particular esters and amides include —CO₂Alk⁵ and —CONR⁸R⁹ groups as described herein.

In general, the substituents R¹, R² and R³ in compounds of the invention may be positioned on any available carbon atom, or, when present, nitrogen atom in the aromatic or heteroaromatic group represented by Ar¹.

When Alk¹ is present in compounds of formula (1) as an optionally substituted aliphatic chain it may be an optionally substituted C₁₋₁₀ aliphatic chain. Particular examples include optionally substituted straight or branched chain C₁₋₆ alkyl, C₂₋₆ alkenyl, or C₂₋₆ alkynyl chains.

Heteroaliphatic chains represented by Alk¹ include the aliphatic chains just described but with each chain additionally containing one, two, three or four heteroatoms or heteroatom-containing groups. Particular heteroatoms or groups include atoms or groups L⁴ where L⁴ is as defined above for L¹ when L¹ is a linker atom or group. Each L⁴ atom or group may interrupt the aliphatic chain, or may be positioned at its terminal carbon atom to connect the chain to an adjoining atom or group.

Particular examples of aliphatic chains represented by Alk¹ include optionally substituted —CH₂—, —CH₂CH₂—, —CH(CH₃)—, —C(CH₃)₂—, —(CH₂)₂CH₂—, —CH(CH₃)CH₂—, —(CH₂)₃CH₂—, —CH(CH₃)CH₂CH₂—, —CH₂CH(CH₃)CH₂—, —C(CH₃)₂CH₂—, —(CH₂)₄CH₂—, —(CH₂) ₅CH₂—, —CHCH—, —CHCHCH₂—, —CH₂CHCH—, —CHCHCH₂CH₂—, —CH₂CHCHCH₂—, —(CH₂)₂CHCH—, —CC—, —CCCH₂—, —CH₂CC—, —CCCH₂CH₂—, —CH₂CCCH ₂—, or —(CH₂)₂CC— chains. Where appropriate each of said chains may be optionally interrupted by one or two atoms and/or groups L⁴ to form an optionally substituted heteroaliphatic chain. Particular examples include optionally substituted —L⁴CH₂—, —CH₂L⁴CH₂—, —L⁴(CH₂)₂—, —CH₂L⁴(CH₂)₂—, —(CH₂)₂L⁴CH₂—, —L⁴(CH₂)₃— and —(CH₂)₂L⁴(CH₂)₂ — chains. The optional substituents which may be present on aliphatic or heteroaliphatic chains represented by Alk¹ include one, two, three or more substituents where each substituent may be the same or different and is selected from halogen atoms, e.g. fluorine, chlorine, bromine or iodine atoms, or C₁₋₆alkoxy, e.g. methoxy or ethoxy, thiol, C₁₋₆alkylthio e.g. methylthio or ethylthio, amino or substituted amino groups. Substituted amino groups include —NHR¹² and —N(R¹²)₂ groups where R¹² is an optionally substituted straight or branched alkyl group as defined below for R¹¹. Where two R¹² groups are present these may be the same or different. Particular examples of substituted chains represented by Alk¹ include those specific chains just described substituted by one, two, or three halogen atoms such as fluorine atoms, for example chains of the type —CH(CF₃)—, —C(CF₃)₂— —CH₂CH(CF₃)—, —CH₂C(CF₃)₂—, —CH(CF₃ )— and —C(CF₃)₂CH₂.

Alk² in the compounds of the invention may be for example a straight or branched C₁₋₃alkylene chain. Particular examples include —CH₂—, —CH(CH₃)— and —(CH₂)₂—.

When in the compounds of formula (1) L¹, L² and/or L³ is present as a linker atom or group it may be any divalent linking atom or group. Particular examples include —O— or —S— atoms or —C(O)—, —C(O)O—, —OC(O)—, —C(S)—, —S(O)—, —S(O)₂—, —N(R¹¹)— [where R¹¹ is a hydrogen atom or an optionally substituted alkyl group], —CON(R¹¹)—, —OC(O)N(R¹¹)—, —CSN(R¹¹)—, —N(R¹¹)CO—, —N(R¹¹)C(O)O—, —N(R¹¹)CS—, —S(O)₂N(R¹¹)—, —N(R¹¹)S(O)₂—, —N(R¹¹)CON(R¹¹)—, —N(R¹¹)CSN(R¹¹)—, or —N(R¹¹)SO₂N(R¹¹)— groups. Where the linker group contains two R¹¹ substituents, these may be the same or different.

When R⁷, R⁸, R⁹, R¹⁰ and/or R¹¹ in the compounds of formula (1) is an alkyl group it may be a straight or branched C₁₋₆alkyl group, e.g. a C₁₋₃alkyl group such as a methyl or ethyl group. Optional substituents which may be present on such groups include for example one, two or three substituents which may be the same or different selected from halogen atoms, for example fluorine, chlorine, bromine or iodine atoms, or hydroxy or C₁₋₆alkoxy e.g. methoxy or ethoxy groups. When Alk³ is present in the compounds of formula (1) as an aliphatic or heteroaliphatic chain it may be for example any of the above-mentioned C₁₋₁₀aliphatic or heteroaliphatic chains described for Alk¹.

Halogen atoms represented by R⁷ in compounds of the invention include fluorine, chlorine, bromine, or iodine atoms.

Examples of th substituents represented by R¹, R², R³, R⁴ and R⁵ in compounds of formula (1) include atoms or groups —L²Alk³L³R⁷, —L²Alk³R⁷, —L²R⁷, —Alk³R⁷ and —R⁷ wherein L², Alk³, L³ and R⁷ are as defined above. Particular examples of such substituents include —L²CH₂L³R⁷, —L²CH(CH₃)L³R⁷, —L²CH(CH₂)₂L³R⁷, —L²CH₂R⁷, —L²CH(CH₃)R⁷, —L²(CH₂)₂R⁷, —CH₂R⁷, —CH(CH₃)R⁷ and —(CH₂)₂R⁷ groups.

Thus each of R¹, R², R³, R⁴ and R⁵ in compounds of the invention may be for example a hydrogen atom, a halogen atom, e.g. a fluorine, chlorine, bromine or iodine atom, or a C₁₋₆alkyl, e.g. methyl, ethyl, n-propyl, i-propyl, n-butyl or t-butyl, C₁₋₆alkylamino, e.g. methylamino or ethylamino, C₁₋₆hydroxyalkyl, e.g. hydroxymethyl or hydroxyethyl, carboxyC₁₋₆alkyl, e.g. carboxyethyl, C₁₋₆alkylthio e.g. methylthio or ethylthio, carboxyC₁₋₆alkylthio, e.g. carboxymethylthio, 2-carboxyethylthio or 3-carboxypropylthio, C₁₋₆alkoxy, e.g. methoxy or ethoxy, C₆₋₁₂arylC₁₋₆alkyloxy e.g. benzyloxy, hydroxyC₁₋₆alkoxy, e.g. 2-hydroxyethoxy, haloC₁₋₆alkyl, e.g. trifluoromethyl, haloC₁₋₆alkoxy, e.g. trifluoromethoxy, C₁₋₆alkylamino, e.g. methylamino or ethylamino, amino (—NH₂), aminoC₁₋₆alkyl, e.g. aminomethyl or aminoethyl, C₁₋₆dialkylamino, e.g. dimethylamino or diethylamino, C₁₋₆alkylaminoC₁₋₆alkyl, e.g. ethylaminoethyl, C₁₋₆dialkylaminoC₁₋₆alkyl, e.g. diethylaminoethyl, aminoC₁₋₆alkoxy, e.g. aminoethoxy, C₁₋₆alkylaminoC₁₋₆alkoxy, e.g. methylaminoethoxy, C₁₋₆dialkylaminoC₁₋₆alkoxy, e.g. dimethylaminoethoxy, diethylaminoethoxy, diisopropylaminoethoxy, or dimethylaminopropoxy, nitro, cyano, amidino, hydroxyl (—OH), formyl [HC(O)—], carboxyl (—CO₂H), —CO₂Alk⁵ [where Alk⁵ is as defined below], C₁₋₆ alkanoyl e.g. acetyl, thiol (—SH), thioC₁₋₆alkyl, e.g. thiomethyl or thioethyl, thioC₁₋₆alkylC₆₋₁₂aryl e.g. thiobenzyl, sulphonyl (—SO₃H), C₁₋₆alkylsulphinyl e.g. methylsulphinyl, C₁₋₆alkylsulphonyl, e.g. methylsulphonyl, aminosulphonyl (—SO₂NH₂), C₁₋₆alkylaminosulphonyl, e.g. methylaminosulphonyl or ethylaminosulphonyl, C₁₋₆dialkylaminosulphonyl, e.g. dimethylaminosulphonyl or diethylamino-sulphonyl, phenylaminosulphonyl, carboxamido (—CONH₂), C₁₋₆alkylaminocarbonyl, e.g. methylaminocarbonyl or ethylaminocarbonyl, C₁₋₆dialkylaminocarbonyl, e.g. dimethylaminocarbonyl or diethylaminocarbonyl, aminoC₁₋₆alkylaminocarbonyl, e.g. aminoethylaminocarbonyl, C₁₋₆dialkylaminoC₁₋₆alkylaminocarbonyl, e.g. diethylaminoethylaminocarbonyl, aminocarbonylamino, C₁₋₆alkylaminocarbonylamino, e.g. methylaminocarbonylamino or ethylaminocarbonylamino, C₁₋₆dialkylaminocarbonylamino, e.g. dimethylaminocarbonylamino or diethylaminocarbonylamino, C₁₋₆alkylaminocabonylC₁₋₆alkylamino, e.g. methylaminocarbonylmethylamino, aminothiocarbonylamino, C₁₋₆alkylaminothiocarbonylamino, e.g. methylaminothiocarbonylamino or ethylaminothiocarbonylamino, C₁₋₆dialkylaminothiocarbonylamino, e.g. dimethylaminothiocarbonylamino or diethylaminothiocarbonylamino, C₁₋₆alkylaminothiocarbonylC₁₋₆alkylamino, e.g. ethylaminothiocarbonylmethylamino, C₁₋₆alkylsulphonylamino, e.g. methylsulphonylamino or ethylsulphonylamino, C₁₋₆dialkylsulphonylamino, e.g. dimethylsulphonylamino or diethylsulphonylamino, aminosulphonylamino (—NHSO₂NH₂), C₁₋₆alkylaminosulphonylamino, e.g. methylaminosulphonylamino or ethylaminosulphonylamino, C₁₋₆dialkylaminosulphonylamino, e.g. dimethylaminosulphonylamino or diethylaminosulphonylamino, C₁₋₆alkanoylamino, e.g. acetylamino, aminoC₁₋₆alkanoylamino e.g. aminoacetylamino, C₁₋₆dialkylaminoC₁₋₆alkanoylamino, e.g. dimethylaminoacetylamino, C₁₋₆alkanoylaminoC₁₋₆alkyl, e.g. acetylaminomethyl, C₁₋₆alkanoylaminoC₁₋₆alkylamino, e.g. acetamidoethylamino, C₁₋₆alkoxycarbonylamino, e.g. methoxycarbonylamino, ethoxycarbonylamino or t-butoxycarbonylamino group.

Aromatic groups represented by the group Ar¹ and/or Ar² in compounds of the invention include for example monocyclic or bicyclic fused ring C₆₋₁₂ aromatic groups, such as phenyl, 1- or 2-naphthyl, 1- or 2-tetrahydronaphthyl, indanyl or indenyl groups. Aromatic groups represented by the group Ar² may be optionally substituted by one, two, three or more R¹³ atoms or groups as defined below.

Heteroaromatic groups represented by the group Ar¹ and/or Ar² in the compounds of formula (1) include for example C₁₋₉ heteroaromatic groups containing for example one, two, three or four heteroatoms selected from oxygen, sulphur or nitrogen atoms. In general, the heteroaromatic groups may be for example monocyclic or bicyclic fused ring heteroaromatic groups. Monocyclic heteroaromatic groups include for example five- or six-membered heteroaromatic groups containing one, two, three or four heteroatoms selected from oxygen, sulphur or nitrogen atoms. Bicyclic heteroaromatic groups include for example eight- to thirteen-membered fused-ring heteroaromatic groups containing one, two or more heteroatoms selected from oxygen, sulphur or nitrogen atoms.

Particular examples of heteroaromatic groups of these types include pyrrolyl, furyl, thienyl, imidazolyl, N—C₁₋₆alkylimidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazole, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, benzofuryl, [2,3-dihydro]benzofuryl, benzothienyl, benzotriazolyl, indolyl, isoindolyl, benzimidazolyl, imidazo[1,2-a]pyridyl, benzothiazolyl, benzoxazolyl, benzopyranyl, [3,4-dihydrol]benzopyranyl, quinazolinyl, qunoxalinyl, naphthyridinyl, pyrido[3,4-b]pyridyl, pyrido[3,2-b]pyridyl, pyrido[4,3-b]-pyridyl, quinolinyl, isoquinolinyl, tetrazolyl, 5,6,7,8-tetrahydroquinolinyl, 5,6,7,8-tetrahydroisoquinolinyl, and imidyl, e.g. succinimidyl, phthalimidyl, or naphthalimidyl such as 1,8-naphthalimidyl.

Optional substituents which may be present on the aromatic or heteroaromatic groups represented by Ar² include one, two, three or more substituents, each selected from an atom or group R¹³ in which R¹³ is —R^(13a) or —Alk⁴(R^(13a))_(m), where R^(13a) is a halogen atom, or an amino (—NH₂), substituted amino, nitro, cyano, amidino, hydroxyl (—OH), substituted hydroxyl, formyl, carboxyl (—CO₂H), esterified carboxyl, thiol (—SH), substituted thiol, —COR¹⁴ [where R¹⁴ is an —Alk³(R^(13a))m, aryl or heteroaryl group], —CSR¹⁴, —SO₃H, —SO₂R¹⁴ —SO₂NH₂, —SO₂NHR¹⁴ SO₂N(R¹⁴)₂, —CONH₂, —CSNH₂, —CONHR¹⁴, —CSNHR¹⁴, —CON[R¹⁴]₂, —CSN(R¹⁴)₂, —N(R¹²)SO₂R¹⁴, —N(SO₂R¹⁴)₂, —NH²(R¹¹)SO₂NH₂, —N(R¹¹)SO₂NHR¹⁴, —N(R¹¹)SO₂N(R¹⁴)₂, —N(R¹¹)COR¹⁴, —N(R¹¹)CON(R¹⁴)₂, —N(R¹¹)CSN(R¹⁴)₂, —N(R¹¹)CSR¹⁴, —N(R¹¹)C(O)OR¹⁴, —SO₂NHet¹ [where —NHet¹ is an optionally substituted C₅₋₇cyclicamino group optionally containing one or more other —O— or —S— atoms or —N(R¹¹)—, —C(O)— or —C(S)— groups], —CONHet¹, —CSNHet¹, —N(R¹¹)SO₂NHet¹, —N(R¹¹)CONHet¹, —N(R¹¹)CSNHet¹, —Het², [where Het² is an optionally substituted monocyclic C₅₋₇carbocyclic group optionally containing one or more —O— or —S— atoms or —N((R¹¹)—, —C(O)— or —C(S)— groups] —SO₂N(R¹¹)Het², —CON(R¹¹)Het², —CSN(R¹¹)Het², —N(R¹¹)CON(R¹¹)Het², —N(R¹¹)CSN(R¹¹)Het², aryl or heteroaryl group; Alk⁴ is a straight or branched C₁₋₆alkylene, C₂₋₆alkenylene or C₂₋₆alkynylene chain, optionally interrupted by one, two or three —O— or —S— atoms or —S(O)_(n) [where n is an integer 1 or 2] or —N(R¹⁵)— groups [where R¹⁵ is a hydrogen atom or C₁₋₆alkyl, e.g. methyl or ethyl group]; and m is zero or an integer 1, 2 or 3. It will be appreciated that when two R¹¹ or R¹⁴ groups are present in one of the above substituents, the R¹¹ or R¹⁴ groups may be the same or different.

When in the group -Alk⁴(R^(13a))_(m) m is an integer 1, 2 or 3, it is to be understood that the substituent or substituents R^(13a) may be present on any suitable carbon atom in -Alk⁴. Where more than one R^(13a) substituent is present these may be the same or different and may be present on the same or different atom in -Alk⁴. Clearly, when m is zero and no substituent R^(13a) is present the alkylene, alkenylene or alkynylene chain represented by Alk⁴ becomes an alkyl, alkenyl or alkynyl group.

When R^(13a) is a substituted amino group it may be for example a group —NHR¹⁴ [where R¹⁴ is as defined above] or a group —N(R¹⁴)₂ wherein each R¹⁴ group is the same or different.

When R^(13a) is a halogen atom it may be for example a fluorine, chlorine, bromine, or iodine atom.

When R^(13a) is a substituted hydroxyl or substituted thiol group it may be for example a group —OR¹⁴ or a —SR¹⁴ or —SC(═NH)NH₂ group respectively.

Esterified carboxyl groups represented by the group R^(13a) include groups of formula —CO₂Alk⁵ wherein Alk⁵ is a straight or branched, optionally substituted C₁₋₈alkyl group such as a methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl group; a C₆₋₁₂arylC₁₋₈alkyl group such as an optionally substituted benzyl, phenylethyl, phenylpropyl, 1-naphthylmethyl or 2-naphthylmethyl group; a C₆₋₁₂aryl group such as an optionally substituted phenyl, 1-naphthyl or 2-naphthyl group; a C₆₋₁₂aryloxyC₁₋₈alkyl group such as an optionally substituted phenyloxymethyl, phenyloxyethyl, 1-naphthyl-oxymethyl, or 2-naphthyloxymethyl group; an optionally substituted C₁₋₈alkanoyloxyC₁₋₈alkyl group, such as a pivaloyloxymethyl, propionyloxyethyl or propionyloxypropyl group; or a C₆₋₁₂aroyloxyC₁₋₈alkyl group such as an optionally substituted benzoyloxyethyl or benzoyloxypropyl group. Optional substituents present on the Alk⁵ group include R^(13a) substituents described above.

When Alk⁴ is present in or as a substituent it may be for example a methylene, ethylene, n-propylene, i-propylene, n-butylene, i-butylene, s-butylene, t-butylene, ethenylene, 2-propenylene, 2-butenylene, 3-butenylene, ethynylene, 2-propynylene, 2-butynylene or 3-butynylene chain, optionally interrupted by one, two, or three —O— or —S—, atoms or —S(O)—, —S(O)₂— or —N(R¹²)— groups.

Aryl or heteroaryl groups represented by the groups R^(13a) or R¹⁴ include mono- or bicyclic optionally substituted C₆₋₁₂ aromatic or C₁₋₉ heteroaromatic groups as described above for the group Ar². The aromatic and heteroaromatic groups may be attached to the remainder of the compound of formula (1) by any carbon or hetero e.g. nitrogen atom as appropriate.

When —NHet¹ or -Het² forms part of a substituent R¹³ each may be for example an optionally substituted pyrrolidinyl, pyrazolidinyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl or thiazolidinyl group. Additionally Het² may represent for example, an optionally substituted cyclopentyl or cyclohexyl group. Optional substituents which may be present on —NHet¹ or -Het² include those R⁷ substituents described above.

Particularly useful atoms or groups represented by R¹³ include fluorine, chlorine, bromine or iodine atoms, or C₁₋₆alkyl, e.g. methyl, ethyl, n-propyl, i-propyl, n-butyl or t-butyl, optionally substituted phenyl, pyridyl, pyrimidinyl, pyrrolyl, furyl, thiazolyl, or thienyl, morpholinyl, thiomorpholinyl, piperazinyl, pyrrolidinyl, piperidinyl, C₁₋₆alkylamino, e.g. methylamino or ethylamino, C₁₋₆hydroxyalkyl, e.g. hydroxymethyl or hydroxyethyl, carboxyC₁₋₆alkyl, e.g. carboxyethyl, C₁₋₆alkylthio e.g. methylthio or ethylthio, carboxyC₁₋₆alkylthio, e.g. carboxymethylthio, 2-carboxyethylthio or 3-carboxypropylthio, C₁₋₆alkoxy, e.g. methoxy or ethoxy, hydroxyC₁₋₆alkoxy, e.g. 2-hydroxyethoxy, optionally substituted phenoxy, pyridyloxy, thiazolyoxy, phenylthio or pyridylthio, C₅₋₇cycloalkoxy, e.g. cyclopentyloxy, haloC₁₋₆alkyl, e.g. trifluoromethyl, haloC₁₋₆alkoxy, e.g. trifluoromethoxy, C₁₋₆alkylamino, e.g. methylamino or ethylamino or propylamino, optionally substituted C₆₋₁₂arylC₁₋₆alkylamino, e.g. benzylamino, fluorobenzylamino or hydroxyphenylethylamino, amino (—NH₂), aminoC₁₋₆alkyl, e.g. aminomethyl or aminoethyl, C₁₋₆dialkylamino, e.g. dimethylamino or diethylamino, aminoC₁₋₆alklamino e.g. aminomethylamino, aminoethylamino or aminopropylamino, Het¹NC₁₋₆alkylamino e.g. morpholinopropylamino, C₁₋₆alkylaminoC₁₋₆alkyl, e.g. ethylaminoethyl, C₁₋₆dialkylaminoC₁₋₆alkyl, e.g. diethylaminoethyl, aminoC₁₋₆alkoxy, e.g. aminoethoxy, C₁₋₆alkylaminoC₁₋₆alkoxy, e.g. methylaminoethoxy, C₁₋₆dialkylaminoC₁₋₆alkoxy, e.g. dimethylaminoethoxy, diethylaminoethoxy, diisopropylaminoethoxy, or dimethylaminopropoxy, hydroxyC₁₋₆alkylamino, e.g. hydroxyethylamino, hydroxypropylamino or hydroxybutylamino, imido, such as phthalimido or naphthalimido, e.g. 1,8-naphthalimido, nitro, cyano, amidino, hydroxyl (—OH), formyl [HC(O)—], carboxyl (—CO₂H), —CO₂Alk⁵ [where Alk⁵ is as defined above], C₁₋₆ alkanoyl e.g. acetyl, propyryl or butyryl, optionally substituted benzoyl, thiol (—SH), thioC₁₋₆alkyl, e.g. thiomethyl or thioethyl, —SC(═NH)NH₂, sulphonyl (—SO₃H), C₁₋₆alkylsulphinyl, e.g. methylsulphinyl, ethylsulphinyl or propylsulphinyl, C₁₋₆ alkylsulphonyl, e.g. methylsulphonyl, ethylsulphonyl, propylsulphonyl, hexylsulphonyl or isobutylsulphonyl, aminosulphonyl (—SO₂NH₂), C₁₋₆ alkylaminosulphonyl, e.g. methylaminosulphonyl, ethylaminosulphonyl or propylaminocsulphonyl, C₁₋₆dialkylaminosulphonyl, e.g. dimethylaminosulphonyl or diethylaminosulphonyl, optionally substituted phenylaminosulphonyl, carboxamido (—CONH₂), C₁₋₆alkylaminocarbonyl, e.g. methylaminocarbonyl, ethylaminocarbonyl or propylaminocarbonyl, C₁₋₆dialkylaminocarbonyl, e.g. dimethylaminocarbonyl, diethylaminocarbonyl or dipropylaminocarbonyl, aminoC₁₋₆alkylaminocarbonyl, e.g. aminoethylaminocarbonyl, C₁₋₆ dialkylaminoC₁₋₆alkylaminocarbonyl, e.g. diethylaminoethylaminocarbonyl, aminocarbonylamino, C₁₋₆alkylaminocarbonylamino, e.g. methylaminocarbonylamino or ethylaminocarbonylamino, C₁₋₆dialkylaminocarbonylamino, e.g. dimethylaminocarbonylamino or diethylaminocarbonylamino, C₁₋₆alkylaminocabonylC₁₋₆alkylamino, e.g. methylaminocarbonylmethylamino, aminothiocarbonylamino, C₁₋₆alkylaminothiocarbonylamino, e.g. methylaminothiocarbonylamino or ethylaminothiocarbonylamino, C₁₋₆ dialkylaminothiocarbonylamino, e.g. dimethylaminothiocarbonylamino or diethylaminothiocarbonylamino, C₁₋₆alkylaminothiocarbonylC₁₋₆alkylamino, e.g. ethylaminothiocarbonylmethylamino, —CONHC(═NH)NH₂, C₁₋₆alkylsulphonylamino, e.g. methylsulphonylamino or ethylsulphonylamino, C₁₋₆dialkylsulphonylamino, e.g. dimethylsulphonylamino or diethylsulphonylamino, optionally substituted phenylsulphonylamino, aminosulphonylamino (—NHSO₂NH₂), C₁₋₆alkylaminosulphonylamino, e.g. methylaminosulphonylamino or ethylaminosulphonylamino, C₁₋₆dialkylaminosulphonylamino, e.g. dimethylaminosulphonylamino or diethylaminosulphonylamino, optionally substituted morpholinesulphonylamino or morpholinesulphonylC₁₋₆alkyl-amino, optionally substituted phenylaminosulphonylamino, C₆₋₁alkanoylamino, e.g. acetylamino, aminoC₁₋₆alkanoylamino e.g. aminoacetylamino, C₁₋₆dialkylaminoC₁₋₆alkanoylamino, e.g. dimethylaminoacetylamino, C₁₋₆ alkanoylaminoC₁₋₆alkyl, e.g. acetylaminomethyl, C₁₋₆alkanoylaminoC₆ alkylamino, e.g. acetamidoethylamino, C₁₋₆alkoxycarbonylamino, e.g. methoxycarbonylamino, ethoxycarbonylamino or t-butoxycarbonylamino or optionally substituted benzyloxy, pyridylmethoxy, thiazolylmethoxy, benzyloxycarbonylamino, benzyloxycarbonylaminoC₁₋₆alkyl e.g. benzyloxycarbonylaminoethyl, thiobenzyl, pyridylmethylthio or thiazolylmethylthio groups.

Where desired, two R¹³ substituents may be linked together to form a cyclic group such as a cyclic ether, e.g. a C₁₋₆alkylenedioxy group such as methylenedioxy or ethylenedioxy.

It will be appreciated that where two or more R¹³ substituents are present, these need not necessarily be the same atoms and/or groups. In general, the substituent(s) may be present at any available ring position in the aromatic or heteroaromatic group represented by Ar².

The presence of certain substituents in the compounds of formula (1) may enable salts of the compounds to be formed. Suitable salts include pharmaceutically acceptable salts, for example acid addition salts derived from inorganic or organic acids, and salts derived from inorganic and organic bases.

Acid addition salts include hydrochlorides, hydrobromides, hydroiodides, alkylsulphonates, e.g. methanesulphonates, ethanesulphonates, or isothionates, arylsulphonates, e.g. p-toluenesulphonates, besylates or napsylates, phosphates, sulphates, hydrogen sulphates, acetates, trifluoroacetates, propionates, citrates, maleates, fumarates, malonates, succinates, lactates, oxalates, tartrates and benzoates.

Salts derived from inorganic or organic bases include alkali metal salts such as sodium or potassium salts, alkaline earth metal salts such as magnesium or calcium salts, and organic amine salts such as morpholine, piperidine, dimethylamine or diethylamine salts.

Particularly useful salts of compounds according to the invention include pharmaceutically acceptable salts, especially acid addition pharmaceutically acceptable salts.

One particular class of compounds of formula (1) is that wherein g is zero.

In the compounds according to the invention the group Ar¹ is preferably a phenyl or monocyclic heteroaromatic group. Particularly useful groups of this type are five- or six-membered heteroaromatic groups as described previously, especially five- or six-membered heteroaromatic groups containing one or two heteroatoms selected from oxygen, sulphur or nitrogen atoms. Nitrogen-containing groups are especially useful, particularly pyridyl or pyrimidinyl groups.

A particularly useful group of compounds according to the invention has the formula (2):

wherein

R¹ and R², which may be the same or different is each an atom or group —L²(Alk³)_(t)L³(R⁷)_(u) in which L², Alk³, t, L³, R⁷ and u are as defined for formula (1) provided that R¹ and R² are not both hydrogen atoms;

Alk¹, Alk², m, r, g, L¹, R⁴, R⁵, R⁶, R^(a), Ar² and R are as defined for formula (1);

and the salts, solvates, hydrates and N-oxides thereof.

R¹ and R² in compounds of formula (2) and in general in compounds of formula (1) is each preferably as particularly described above for compounds of formula (1), other than a hydrogen atom. Particularly useful R¹ and R² substituents include halogen atoms, especially fluorine or chlorine atoms, or methyl, halomethyl, especially —CF₃, —CHF₂ or —CH₂F, methoxy or halomethoxy, especially —OCF₃, —OCHF₂ or —OCH₂F groups.

R³ in compounds of the invention is in particular a hydrogen atom.

R in the compounds of formulae (1) and (2) is preferably a —CO₂H group.

When present, the aliphatic chain represented by Alk¹ in compounds of formulae (1) and (2) is preferably a —CH₂— chain.

In general in compounds of formulae (1) and (2) -(Alk¹)_(r)L¹— is preferably —CH₂O— or —CON(R¹¹)—. A particularly useful group is —CONH—.

In compounds of formulae (1) and (2) m is preferably 1 and Alk² is preferably —CH₂—; g in these compounds is preferaly zero.

R⁴ and R⁵ in the compounds of formulae (1) and (2) may be the same or different and is each preferably a hydrogen or halogen atom or an alkyl, alkoxy, hydroxy, nitro, cyano or —NR⁸R⁹ group.

R⁶ and R^(a) in the compounds of formulae (1) and (2) is each preferably a hydrogen atom.

Particularly useful classes of compounds according to the invention are those wherein Ar² is an optionally substituted monocyclic aromatic or heteroaromatic group. One especially useful aromatic group when represented by Ar² is phenyl. Especially useful heteroaromatic groups represented by Ar² include optionally substituted monocyclic nitrogen-containing heteroaromatic groups, particularly optionally substituted pyridyl, pyrimidinyl , pyridazinyl and triazinyl groups. Where the group is a triazinyl group it is preferably a 1,3,5 triazine.

Optional substituents which may be present on preferred Ar² aromatic or heteroaromatic groups include for example one or two substituents selected from those R¹³ substituents described above.

Particularly useful R¹³ substituents of these types include a halogen atom, especially fluorine or chlorine, morpholinyl, thiomorpholinyl, optionally substituted piperidinyl, especially piperidinyl or 4-carboxypiperidinyl, pyrrolidinyl, optionally substituted piperazinyl, especially t-butyloxycarbonylpiperazinyl, thioC₁₋₆alkyl, especially thiomethyl, thioethyl or thiopropyl, optionally substituted thiobenzyl, especially thiobenzyl, haloC₁₋₆alkyl, especially trifluoromethyl, C₁₋₆alkyloxy, especially methoxy, ethoxy or propoxy, optionally substituted benzyloxy, especially benzyloxy, haloC₁₋₆alkoxy, especially trifluoromethoxy and difluoromethoxy, C₁₋₆alkylamino, especially methylamino, ethylamino or propylamino, C₁₋₆dialkylamino, especially dimethylamino or diethylamino, optionally substituted C₆₋₁₂arylC₁₋₆alkylamino, especially benzylamino, 4-substituted benzyl, especially 4-fluorobenzylamino or 4-hydroxyphenylethylamino, aminoalkylamino, especially 3-aminopropylamino, Het¹NC₁₋₆alkylamino, especially 3-morpholinopropylamino, optionally substituted phenoxy, especially phenoxy, hydroxyC₁₋₆alkylamino, especially 2-hydroxyethylamino, 3-hydroxypropylamino and 3-hydroxybutylamino, nitro, carboxyl, —CO₂Alk⁵ [where R⁵ is as defined above], especially carboxymethyl and carboxyethyl, carboxamido, C₁₋₆alkylaminocarbonyl, especially methylaminocarbonyl, ethylaminocarbonyl and propylaminocarbonyl, C₁₋₆dialkylaminocarbonyl, especially dimethylaminocarbonyl, diethylaminocarbonyl or dipropylaminocarbonyl, C₁₋₆alkanoyl, especially acetyl, propyryl or butyryl, optionally substituted benzoyl, especially benzoyl, C₁₋₆alkylsulphinyl, especially methylsulphinyl, ethylsulphinyl or propylsulphinyl, C₁₋₆alkylsulphonyl, especially methylsulphonyl, ethylsulphonyl, propylsulphonyl, hexylsulphonyl or isobutylsulphonyl, C₁₋₆alkylaminosulphonyl, especially ethylaminosulfonyl or propylaminosulphonyl, C₁₋₆dialkylaminosulphonyl, especially diethylaminosulphonyl, C₁₋₆alkylaminocarbonyl, especially methylaminocarbonyl, ethylaminocarbonyl or propylaminocarbonyl, C₁₋₆dialkylaminocarbonyl, especially dimethylaminocarbonyl or diethylaminocarbonyl.

Particularly useful Alk⁴ groups when present in compounds of the invention include —CH₂—, —CH₂CH₂—, —(CH₂)₂CH₂— —CH(CH₃)CH₂— and —(CH₂)₃CH₂— groups.

Particularly useful compounds of the invention include:

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylsulphinylpyrimidin-4-ylamino)propanoic acid;

S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[3,5-dichloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methoxy-2-methylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-D ichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methoxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-(2-hydroxyethylamino)-1,3,5-triazin-2-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-(4-carboxypiperidinyl)-1,3,5-triazin-2-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-piperazinyl-1,3,5-triazin-2-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methyl-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-benzylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-carboxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-chloropyridazin-3-yl-amino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylpyrazin-2-ylamino)propanoic acid;

3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylbenzeneamino)propanoic acid;

3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphonylpyridin-2-ylamino)propanoic acid;

3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-propylsulphonylpyridin-2-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-trifluoromethylpyrimidin-2-ylamino)propanoic acid;

S-3-[4-(3,5-Dichloro-1-oxidopyridino-4-ylcarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylaminoamino)propanoic acid;

S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-methoxy-6-(3-hydroxypropylamino)1,3,5-triazin-2-ylamino]propanoic acid;

and the salts, solvates, hydrates and N-oxides thereof.

Compounds according to the invention are potent and selective inhibitors of α4 integrins. The ability of the compounds to act in this way may be simply determined by employing tests such as those described in the Examples hereinafter.

The compounds are of use in modulating cell adhesion and in particular are of use in the prophylaxis and treatment of diseases or disorders involving inflammation in which the extravasation of leukocytes plays a role and the invention extends to such a use and to the use of the compounds for the manufacture of a medicament for treating such diseases or disorders.

Diseases or disorders of this type include inflammatory arthritis such as rheumatoid arthritis vasculitis or polydermatomyositis, multiple sclerosis, allograft rejection, diabetes, inflammatory dermatoses such as psoriasis or dermatitis, asthma and inflammatory bowel disease.

For the prophylaxis or treatment of disease the compounds according to the invention may be administered as pharmaceutical compositions, and according to a further aspect of the invention we provide a pharmaceutical composition which comprises a compound of formula (1) together with one or more pharmaceutically acceptable carriers, excipients or diluents.

Pharmaceutical compositions according to the invention may take a form suitable for oral, buccal, parenteral, nasal, topical or rectal administration, or a form suitable for administration by inhalation or insufflation.

For oral administration, the pharmaceutical compositions may take the form of, for example, tablets, lozenges or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g. pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g. lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g. magnesium stearate, talc or silica); disintegrants (e.g. potato starch or sodium glycollate); or wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents, emulsifying agents, non-aqueous vehicles and preservatives. The preparations may also contain buffer salts, flavouring, colouring and sweetening agents as appropriate.

Preparations for oral administration may be suitably formulated to give controlled release of the active compound.

For buccal administration the compositions may take the form of tablets or lozenges formulated in conventional manner.

The compounds for formula (1) may be formulated for parenteral administration by injection e.g. by bolus injection or infusion. Formulations for injection may be presented in unit dosage form, e.g. in glass ampoule or multi dose containers, e.g. glass vials. The compositions for injection may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising, preserving and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use.

In addition to the formulations described above, the compounds of formula (1) may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation or by intramuscular injection.

For nasal administration or administration by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation for pressurised packs or a nebuliser, with the use of suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas or mixture of gases.

The compositions may, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active ingredient. The pack or dispensing device may be accompanied by instructions for administration.

The quantity of a compound of the invention required for the prophylaxis or treatment of a particular condition will vary depending on the compound chosen, and the condition of the patient to be treated. In general, however, daily dosages may range from around 100 ng/kg to 100 mg/kg e.g. around 0.01 mg/kg to 40mg/kg body weight for oral or buccal administration, from around 10 ng/kg to 50 mg/kg body weight for parenteral administration and around 0.05 mg to around 1000 mg e.g. around 0.5 mg to around 1000 mg for nasal administration or administration by inhalation or insufflation.

The compounds of the invention may be prepared by a number of processes as generally described below and more specifically in the Examples hereinafter. In the following process description, the symbols R¹-R⁶, Ar¹, L¹, Alk¹, Alk², m, r, g, Ar², R^(a) and R when used in the formulae depicted are to be understood to represent those groups described above in relation to formula (1) unless otherwise indicated. In the reactions described below, it may be necessary to protect reactive functional groups, for example hydroxy, amino, thio or carboxy groups, where these are desired in the final product, to avoid their unwanted participation in the reactions. Conventional protecting groups may be used in accordance with standard practice [see, for example, Green, T. W. in “Protective Groups in Organic Synthesis”, John Wiley and Sons, 1991]. In some instances, deprotection may be the final step in the synthesis of a compound of formula (1) and the processes according to the invention described hereinafter are to be understood to extend to such removal of protecting groups. For convenience the processes described below all refer to a preparation of a compound of formula (1) but clearly the description applies equally to the preparation of compounds of formula (2).

Thus according to a further aspect of the invention, a compound of formula (1) in which R is a —CO₂H group may be obtained by hydrolysis of an ester of formula (3):

where R^(b) is an alkyl group, for example a C₁₋₆alkyl group as described above.

The hydrolysis may be performed using either an acid or a base depending on the nature of R^(b), for example an organic acid such as trifluoroacetic acid or an inorganic base such as lithium or potassium hydroxide optionally in an aqueous organic solvent such as an amide, e.g. a substituted amide such as dimethylformamide, an ether, e.g. a cyclic ether such as tetrahydrofuran or dioxane or an alcohol, e.g. methanol at around ambient temperature. Where desired, mixtures of such solvents may be used.

Esters of formula (3) may be prepared by coupling an amine of formula (4):

or a salt thereof with a reagent Ar²X¹ where X¹ is a leaving group. Particular leaving groups represented by X¹ include for example halogen atoms such as fluorine, chlorine or bromine atoms or sulphonyloxy groups such as a methylsulphonyloxy group.

The coupling reaction may be performed using standard conditions for reactions of this type. Thus for example the reaction may be carried out in a solvent, for example an alcohol, e.g. methanol or ethanol, at a temperature from around ambient to the reflux temperature, optionally in the presence of a base, e.g. an organic base such as an amine, e.g. triethylamine or N,N-diisopropylethylamine, or a cyclic amine, such as N-methylmorpholine or pyridine.

In a further example compounds of formula (4) [R^(a), R⁶ are H, g is zero] can be converted into compounds of formula (5) by treatment with nitrous acid,or isoamyl nitrite in the presence of an acid source, for example acetic acid, in a halogenated hydrocarbon e.g. dichloromethane or chloroform at a temperature from ambient temperature to 60° C.

Esters of formula (3) can be obtained from diazo compounds of formula (5) by reaction with amines of formula Ar²R^(a)NH optionally in the presence of a catalyst, for example a rhodium (II) catalyst, for example rhodium (II) acetate dimer, a copper (II) catalyst, for example copper (II) acetate or a palladium (II) catalyst, for example palladium (II) acetate in an organic solvent, e.g. toluene, at a temperature from around ambient to the reflux temperature.

Where desired, compounds of formula (4) may be linked to a suitable solid support, for example via their carboxylate group (R^(b) is H), and subsequently converted to compounds of formula (1) linked to the solid support via the methods just described. Displacement from the resin by any convenient method for example by cleavage using an acid such as trifluoroacetic acid, then gives the desired compound of formula (1).

Particular examples of such solid-phase syntheses are given in the Examples herein.

The amines of formula (4) may be obtained from simpler, known compounds by one or more standard synthetic methods employing C—C bond formation substitution, 1,4-addition, oxidation, reduction or cleavage reactions. Particular C—C bond forming reactions include the Horner-Emmons and Wittig reactions. Particular substitution approaches include conventional alkylation, arylation, heteroarylation, acylation, thioacylation, halogenation, sulphonylation, nitration, formylation and coupling procedures. It will be appreciated that these methods may also be used to obtain or modify other compounds of formulae (1) and (2) where appropriate functional groups exist in these compounds. Additionally, although a number of the intermediates Ar²X¹ for use in the coupling reaction described above are known, others can be derived therefrom using these standard synthetic methods.

Thus compounds of the invention and intermediates thereto may be prepared by alkylation, arylation or heteroarylation. For example, compounds containing a —L¹H, —L²H, or —L³H group (where L¹, L² and L³ is each a linker atom or group) may be treated with an alkylating agent:

(R⁷)_(u)L³Alk³ _(t)X² or R^(7a)X² respectively in which X² is a leaving atom or group such as a halogen atom, e.g. a fluorine, bromine, iodine or chlorine atom or a sulphonyloxy group such as an alkylsulphonyloxy, e.g. trifluoromethylsulphonyloxy or arylsulphonyloxy, e.g. p-toluenesulphonyloxy group, and R^(7a) is an alkyl group.

The reaction may be carried out in the presence of a base such as a carbonate, e.g. caesium or potassium carbonate, an alkoxide, e.g. potassium t-butoxide, or a hydride, e.g. sodium hydride, in a dipolar aprotic solvent such as an amide, e.g. a substituted amide such as dimethylformamide or an ether, e.g. a cyclic ether such as tetrahydrofuran.

In another example, compounds containing a —L¹H, —L²H or —L³H group as defined above may be functionalised by acylation or thioacylation, for example by reaction with one of the alkylating agents just described but in which X² is replaced by a —C(O)X³, C(S)X³, —N(R⁸)COX³ or —N(R⁸)C(S)X³ group in which X³ is a leaving atom or group as described for X². The reaction may be performed in the presence of a base, such as a hydride, e.g. sodium hydride or an amine, e.g. triethylamine or N-methylmorpholine, in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane or carbon tetrachloride or an amide, e.g. dimethylformamide, at for example ambient temperature. Alternatively, the acylation or thioacylation may be carried out under the same conditions with an acid or thioacid (for example one of the alkylating agents described above in which X² is replaced by a —CO₂H or —COSH group) in the presence of a condensing agent, for example a diimide such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide or N,N′-dicyclohexylcarbodiimide, advantageously in the presence of a catalyst such as a N-hydroxy compound e.g. a N-hydroxytriazole such as 1-hydroxybenzotriazole. Alternatively the acid may be reacted with a chloroformate, for example ethylchloroformate, prior to the desired acylation reaction.

In a further example compounds may be obtained by sulphonylation of a compound containing an —OH group by reaction with one of the above alkylating agents but in which X² is replaced by a —S(O)Hal or —SO₂Hal group in which Hal is a halogen atom such as chlorine atom] in the presence of a base, for example an inorganic base such as sodium hydride in a solvent such as an amide, e.g. a substituted amide such as dimethylformamide at for example ambient temperature.

In another example, compounds containing a —L¹ H, —L²H or —L³H group as defined above may be coupled with one of the alkylation agents just described but in which X² is replaced by an —OH group in a solvent such as tetrahydrofuran in the presence of a phosphine, e.g. triphenylphosphine and an activator such as diethyl, diisopropyl- or dimethylazodicarboxylate.

In a further example, ester groups —CO₂R⁸ or —CO₂Alk⁵ in the compounds may be converted to the corresponding acid [—CO₂H] by acid- or base-catalysed hydrolysis depending on the nature of the groups R⁸ or Alk⁵. Acid- or base-catalysed hydrolysis may be achieved for example by treatment with an organic or inorganic acid, e.g. trifluoroacetic acid in an aqueous solvent or a mineral acid such as hydrochloric acid in a solvent such as dioxan or an alkali metal hydroxide, e.g. lithium hydroxide in an aqueous alcohol, e.g. aqueous methanol.

In a further example, —OR⁸ or —OR¹⁴ groups [where R⁸ or R¹⁴ each represents an alkyl group such as methyl group] in compounds of formula (1) may be cleaved to the corresponding alcohol —OH by reaction with boron tribromide in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane at a low temperature, e.g. around −78° C.

Alcohol [—OH] groups may also be obtained by hydrogenation of a corresponding —OCH₂R¹⁴ group (where R¹⁴ is an aryl group) using a metal catalyst, for example palladium on a support such as carbon in a solvent such as ethanol in the presence of ammonium formate, cyclohexadiene or hydrogen, from around ambient to the reflux temperature. In another example, —OH groups may be generated from the corresponding ester [—CO₂Alk⁵ or CO₂R⁸] or aldehyde [—CHO] by reduction, using for example a complex metal hydride such as lithium aluminium hydride or sodium borohydride in a solvent such as methanol.

In another example, alcohol —OH groups in the compounds may be converted to a corresponding —OR⁸ group by coupling with a reagent R⁸OH in a solvent such as tetrahydrofuran in the presence of a phosphine, e.g. triphenylphosphine and an activator such as diethyl-, diisopropyl-, or dimethylazodicarboxylate.

Aminosulphonylamino [—NHSO₂NH₂] groups in the compounds may be obtained, in another example, by reaction of a corresponding amine [—NH₂] with sulphamide in the presence of an organic base such as pyridine at an elevated temperature, e.g. the reflux temperature.

In a further example amine (—NH₂) groups may be alkylated using a reductive alkylation process employing an aldehyde and a borohydride, for example sodium triacetoxyborohyride or sodium cyanoborohydride, in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane, a ketone such as acetone, or an alcohol, e.g. ethanol, where necessary in the presence of an acid such as acetic acid at around ambient temperature.

In a further example, amine [—NH₂] groups in compounds of formula (1) may be obtained by hydrolysis from a corresponding imide by reaction with hydrazine in a solvent such as an alcohol, e.g. ethanol at ambient temperature.

In another example, a nitro [—NO₂] group may be reduced to an amine [—NH₂], for example by catalytic hydrogenation using for example hydrogen in the presence of a metal catalyst, for example palladium on a support such as carbon in a solvent such as an ether, e.g. tetrahydrofuran or an alcohol e.g. methanol, or by chemical reduction using for example a metal, e.g. tin or iron, in the presence of an acid such as hydrochloric acid.

Aromatic halogen substituents in the compounds may be subjected to halogen-metal exchange with a base, for example a lithium base such as n-butyl or t-butyl lithium, optionally at a low temperature, e.g. around −78° C., in a solvent such as tetrahydrofuran and then quenched with an electrophile to introduce a desired substituent. Thus, for example, a formyl group may be introduced by using dimethylformamide as the electrophile; a thiomethyl group may be introduced by using dimethyidisulphide as the electrophile.

In another example, sulphur atoms in the compounds, for example when present in a linker group L¹, L² or L³ may be oxidised to the corresponding sulphoxide or sulphone using an oxidising agent such as a peroxy acid, e.g. 3-chloroperoxybenzoic acid, in an inert solvent such as a halogenated hydrocarbon, e.g. dichloromethane, at around ambient temperature.

N-oxides of compounds of formula (1) may be prepared for example by oxidation of the corresponding nitrogen base using an oxidising agent such as hydrogen peroxide in the presence of an acid such as acetic acid, at an elevated temperature, for example around 70° C. to 80° C., or alternatively by reaction with a peracid such as peracetic acid in a solvent, e.g. dichloromethane, at ambient temperature.

Salts of compounds of formula (1) may be prepared by reaction of a compound of formula (1) with an appropriate base in a suitable solvent or mixture of solvents e.g. an organic solvent such as an ether e.g. diethylether, or an alcohol, e.g. ethanol using conventional procedures.

Where it is desired to obtain a particular enantiomer of a compound of formula (1) this may be produced from a corresponding mixture of enantiomers using any suitable conventional procedure for resolving enantiomers.

Thus for example diastereomeric derivatives, e.g. salts, may be produced by reaction of a mixture of enantiomers of formula (1) e.g. a racemate, and an appropriate chiral compound, e.g. a chiral base. The diastereomers may then be separated by any convenient means, for example by crystallisation and the desired enantiomer recovered, e.g. by treatment with an acid in the instance where the diastereomer is a salt.

In another resolution process a racemate of formula (1) may be separated using chiral High Performance Liquid Chromatography. Alternatively, if desired a particular enantiomer may be obtained by using an appropriate chiral intermediate in one of the processes described above.

Chromatography, recrystalliation and other conventional separation procedures may also be used with intermediates or final products where it is desired to obtain a particular geometric isomer of the invention.

The following Examples illustrate the invention. All temperatures are in ° C. The following abbreviations are used:

NMM—N—methylmorpholine; EtOAc—ethyl acetate; MeOH—methanol; BOC—butoxycarbonyl; DCM—dichloromethane, ACOH—acetic acid; DIPEA—N,N-diisopropylethylamine; DMF—dimethylformamide; LDA—lithium N,N-diisopropylamide; mCPBA—3-chloroperoxybenzoic acid

All NMR's were obtained at 300mHz.

Intermediate 1

3.5-Dichloropyridine-4-carboxylic acid

A solution of 3,5-dichloropyridine (5.00 g, 33.8 mmol) in THF (25 ml) was added to a solution of LDA [generated from nBuLi (2.5M solution hexanes, 14.9 ml, 37.2 mmol) and diisopropylamine (4.10 g, 5.7 ml, 40.6 mmol)] in THF (25 ml) at −78° then CO₂ gas was bubbled through to give a clear brown solution that slowly gave a precipitate, warmed to room temperature over 2 h, then quenched with water (20 ml) and partitioned between diethylether (100 ml) and 1M NaOH (100 ml). The aqueous layer was separated and acidified to pH1 with concentrated hydrochloric acid and then extracted with 10% MeOH in DCM (100 ml×3). The combined organic layers were dried (MgSO₄) and the solvent removed in vacuo to give a brown solid that was recrystallised from ethanol and dried under vacuum to give the title compound as pinkish crystals (2.63 g, 41%): δH (DMSO d₆) 8.72 (2H, s).

Intermediate 2

(S)-Ethyl-3-[4-(3.5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(t-butoxycarbonylamino)propionate

A slurry of Intermediate 1 (51.2 g, 0.267 mol) in DCM (195 ml) and thionyl chloride (195 ml, 2.67 mol) was treated with DMF (5 drops) and heated to reflux for 4 h. The reaction was concentrated in vacuo and azeotroped with toluene (2×50ml) to give the acid chloride derivative of intermediate 1 as a yellow solid which was used without further purification. A solution of (S)-ethyl-3-(4-aminophenyl)-2-(t-butoxycarbonylamino)propionate (130.8 g, 0.425 mol) in DCM (800 ml) was cooled to 0° and treated with NMM (56.0 ml, 0.51 mol), stirred 5 minutes and then a solution of the acid chloride (98.3 g, 0.468 mol) in DCM (200 ml) was added dropwise keeping the reaction temperature below 5°. The reaction was stirred for 1 h, quenched with NaHCO₃ solution (500 ml), the organic layer separated, washed with NaHCO₃ solution (500 ml), 10% citric acid solution (500 ml) and NaHCO₃ solution (500 ml), dried (MgSO₄) and concentrated in vacuo to give a yellow solid which was recrystallised (EtOAc/Hexane) to give the title compound (140 g, 69%): δH (DMSO d₆) 8.80 (2H, s), 7.55 (2H, d, J 8.5 Hz), 7.23 (2H, d, J 8.5 Hz), 4.00 (3H, m), 3.40 (2H, br. s), 2.90 (1H, m), 2.80 (1H, m), 1.30 (9H, s), 1.25 (3H, t); m/z (EI⁺, 70V) 504.

Intermediate 3

(S)-Ethyl-3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-aminopropionate hydrochloride

A solution of Intermediate 2 (70.0 g, 0.146 mol) in EtOAc (500 ml) and 1,4-dioxan (50 ml) was treated with a solution of HCl in EtOAc (500 ml, 3M), and stirred at room temperature for 4 h. The reaction was concentrated in vacuo to give a yellow soild which was triturated with Et₂O then recrystallised (EtOAc/hexane) to give the title compound (59.3 g, 92%): δH (DMSO d₆) 11.10 (1H, s), 8.70 (2H, s), 7.55 (2H, d, J 8.4 Hz), 7.25 (2H, d, J 8.4 Hz), 4.10 (3H, m), 3.10 (2H, m), 1.10 (3H, m); m/z (EI⁺, 70V) 382.

Intermediate 4

(S)-Methyl-3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-aminopropionate hydrochloride

The title compound was prepared in a similar manner to Intermediate 3 starting from (S)-methyl-3-(4-aminophenyl)-2-(t-butoxycarbonylamino)propionate and Intermediate 1: δH (DMSO d₆) 11.08 (1H, s), 8.77 (2H, s), 8.73 (3H, br. m), 7.63 (2H, d, J 8.5 Hz), 7.25 (2H, d, J 8.5 Hz), 4.24 (1H, m), 3.70 (3H, s), 3.16 (2H, m); m/z (EI⁺, 70V) 368 and 370.

Intermediate 5

3,5-Dichloro-4-hydroxymethylpyridine

A solution of 3,5-dichloropyridine-4-carboxaldehyde (1.34 g, 7.6 mmol) in MeOH (10 ml) was treated with NaBH₄ (0.29 g, 7.6 mmol) and stirred at room temperature for 2 h. The reaction was quenched with water (5 ml) and concentrated in vacuo. The residue was partitioned between EtOAc (20 ml) and 10% HCl (10 ml). The aqueous layer was extracted with EtOAc and the combined organic extracts washed with 10% NaHCO₃ solution, dried (MgSO₄) and concentrated in vacuo to give the title compound as a white solid (1.05 g, 78%): δH (CDCl₃) 8.52 (2H, s), 4.94 (2H, br. s), 2.28 (1H, br. s).

Intermediate 6

3,5-Dichloro-4-bromomethylpyridine

A solution of Intermediate 5 (0.50 g, 2.80 mmol) in DCM (10 ml) was treated with thionyl bromide (3.51 g, 1.32 ml, 16.9 mmol) and heated to reflux for 3 h. The reaction was quenched with 10% NaHCO₃ solution (10 ml) and extracted with DCM (25 ml). The organic layer was dried (MgSO₄) and concentrated in vacuo to give the title compound as a yellow oil that solidified on standing (0.65 g, 96%) and was used without further purification: δH (CDCl₃) 8.50 (2H, s), 4.63 (2H, s); m/z (EI⁺, 60V) 242.

Intermediate 7

(S)-Ethyl-[O-(3,5-dichloropyrid-4-yl)methyl]-L-tyrosine hydrochloride

The title compound was obtained by reaction of N-Boc-L-tyrosine ethyl ester with Intermediate 6 in the presence of sodium hydride, followed by Boc deprotection, using methods well known to a person skilled in the art: δH (DMSO d₆) 8.79-8.60 (3H, m), 7.20 (2H, d, J 8.6 Hz), 7.00 (2H, d, J 8.6 Hz), 5.21 (2H, s), 4.34-4.20 (1H, m), 3.67 (3H, s); m/z (EI⁺, 70V) 355 and 357.

Intermediate 8

S-Ethyl 3-(4-nitrophenyl)-2-(6-chloropyrimidin-4-ylamino)propionate

A solution of 4-nitro-L-phenylalanine ethyl ester (3.22 g, 13.53 mmol), DIPEA (2.35 ml, 1.75 g, 13.56 mmol) and 4,6-dichloropyrimidine (2.02 g, 13.55 mmol) in absolute ethanol (16 ml) was stirred at 70° for 18 h under N₂. The volatiles were removed in vacuo and the residue partitioned between EtOAc (70 ml) and water (40 ml). The phases were separated and the aqueous phase re-extracted with EtOAc (2×30 ml). The combined organic extracts were washed with brine (10 ml), dried (Na₂SO₄) and evaporated in vacuo to afford a dark oil. Chromatography (silica, 2% MeOH/DCM) afforded the title compound as an orange oil which slowly solidified (4.03 g, 85%); δH (CDCl₃,) 8.39 (1H, s), 8.13 (2H, d, J 8.7 Hz), 7.28 (2H, d, J 8.7 Hz), 6.43 (1H, s), 5.55 (1H, br d, J 7.0 Hz), 5.10-5.00 (1H, br m), 4.21 (2H, q, J 7.1 Hz), 3.27 (1H, dd, J 13.8, 6.0 Hz), 3.27 (1H, dd, J 13.8, 5.7 Hz) and 1.26 (3H, t, J 7.1 Hz); m/z (EI⁺, 100V) 351.

Intermediate 9

S-Ethyl 3-(4-aminophenyl)-2-(6-chloropyrimidin-4-ylamino)propionate

A mixture of Intermediate 8 (1 g, 2.85 mmol) and 10% palladium on activated carbon (100 mg) in absolute ethanol (40 ml) was stirred under a hydrogen atmosphere (balloon) at room temperature for 1.5 h. After degassing and N₂ flushing, the catalyst was removed by filtration through a Celite® pad and washed with DCM. The filtrate was evaporated in vacuo and the obtained yellow oil subjected to chromatorgaphy (silica: 3% MeOH/DCM). The title compound was isolated as a yellow oil (0.42 g, 46%) δH (CDCl₃) 8.33 (1H, s), 6.86 (2H, d, J 8.4 Hz), 6.56 (2H, d, J 8.4 Hz), 6.30 (1H, s), 5.27 (1H, br s), 4.84 (1H, br s), 4.19 (2H, q, J 7.1 Hz), 3.64 (2H, br s), 3.10 (1H, dd, J 14.0, 5.6 Hz), 3.01 (1H, dd, J 14.0, 6.1 Hz) and 1.26 (3H, t, J 7.1 Hz); m/z (EI⁺, 100V) 321.

Intermediate 10

S-Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-chloro-1,3,5-triazin-2-ylamino)propionate

Intermediate 3 (0.5 g, 1.19 mmol) in dry acetonitrile (5 ml) under nitrogen was added to 2,4 dichloro-6-methoxy-1,3,5-triazine (0.26 g, 1.43 mmol). The mixture was cooled to −30° and DIPEA (0.46 ml) was added slowly over 10 min. The reaction was allowed to warm to 50° over 2 h and then ethyl acetate and aqueous sodium bicarbonate were added and the mixture shaken and separated. The organic layer was washed with water, dried (MgSO₄) and the solvent removed in vacuo. The product was purified by flash chromatography (silica; EtOAC/Hexane 1:1) to afford the title compound as a white solid (0.53 g, 85%): δH (DMSO d₆) 10.55 (1H, s), 8.70 (2H, s), 8.51-8.40 (1H,m), 7.50 (2H, d, J 8.4 Hz), 7.29 (2H, d, J 8.4 Hz), 4.60 (1H, m), 4.12 (2H, d, J 8.4 Hz), 3.87 (3H, s), 3.23-3.15 (2H, m), 1.16 (3H, t, J 7.2 Hz); m/z (EI⁺, 70V) 527.

Intermediate 11

S-Ethyl 3-(4-hydroxyphenyl)-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

A mixture of L-tyrosine ethyl ester hydrochloride (0.50 g, 2.0 mmol) and DIPEA (0.74 ml, 4.4 mmol) in CH₃CN (8 ml) was stirred at room temperature for 15 minutes and then 2-chloro-4,6-dimethoxy-1,3,5-triazine (0.43 g, 2.2 mmol) was added, and the reaction stirred overnight then concentrated in vacuo. The residue was partitioned between EtOAc (50 ml) and NaHCO₃ solution (50 ml). The organic layer was washed with 10% citric acid solution (50 ml), NaHCO₃ solution (50 ml) and water (50 ml), dried (MgSO₄) and concentrated in vacuo to give the title compound as a colourless gum (0.48 g, 68%): δH (DMSO d₆) 6.90 (2H, d), 6.65 (2H, d), 5.90 (1H, m), 4.90 (1H, m), 4.10 (2H, m), 3.95 (3H, s), 3.90 (3H, s), 3.10 (2H, m), 1.20 (3H, t, J 7.1 Hz); m/z (EI⁺, 70V) 349.

Intermediate 12

2.3-Bis(propylsulphonyl)pyrazine

Propanethiol (1.99 ml, 22mmol) was added to a suspension of sodium hydride (60% in mineral oil, 880 mg, 22 mmol) in THF (50 ml). After 10 min, a solution of 2,3-dichloropyrazine (1.49 g, 10 mmol) in THF (15 ml) was added and the mixture stirred at room temperature overnight. The reaction was quenched with water and the solvent removed in vacuo. The residue was dissolved in EtOAc, washed with water, 10% NaOH solution and brine, dried (Na₂SO₄) and evaporated in vacuo to give a pale yellow oil (2.7 g). This was dissolved in DCM (100 ml) at 0°, and mCPBA (57-86%, ˜40 mmol, 12.1 g) was added in portions. The mixture was stirred at room temperature overnight, then treated with Na₂SO₃ (aq). The organic phase was washed with NaHCO₃ (aq), dried (Na₂SO₄) and evaporated in vacuo to give the title compound as a white solid (3.18 g): δH (CDCl₃) 8.94 (2H, s), 3.68-3.63 (4H, m), 2.10-1.88 (4H, m), 1.10 (6H, t, J 7.4 Hz); m/z (EI⁺, 70V) 293.

Intermediate 13

4.6-Bis(propylsulphonyl)pyrimidine

The title compound was prepared by the method of Intermediate 12 from 4,6-dichloropyrimidine: δH (DMSO d₆) 9.77 (1H, d, J 1.3 Hz), 8.40 (1H, d, J 1.3 Hz), 3.61˜3.56 (4H, m), 1.75-1.65 (4H, m), 0.97 (6H, t, J 7.5 Hz); m/z (EI⁺, 70V) 293.

Intermediate 14

2-Chloro-3-phenoxyquinoxaline

A solution of phenol (564 mg, 6 mmol) in THF (5 ml) was added to a suspension of sodium hydride (60% in mineral oil, 240 mg, 6 mmol) in THF (10 ml). After 10 min 2,3-dichloroquinoxaline (995 mg, 5 mmol) was added. The mixture was stirred for 3 days. The solvent was removed in vacuo, the residue was dissolved in EtOAc, washed with NaOH (1M), dried (Na₂SO4) and evaporated in vacuo to give a yellow solid. Recrystallisation from diisopropylether gave the title compound as off-white needles: δH (DMSO d₆) 8.01-7.98 (1H, m), 7.77-7.67 (3H, m), 7.53-7.48 (2H, m), 7.37-7.30 (3H, m); m/z (EI⁺, 70V) 257.

Intermediate 15

Ethyl 2-(diethoxyphosphoryl)-3-(4-nitrophenyl)propionate

Ethyl 2-(diethoxyphosphoryl)acetate (5.0 ml, 25.2 mmol) was added to a suspension of sodium hydride (60% in mineral oil, 1.10 g, 27.6 mmol) in THF (40 ml) at 0°. After 30 min at room temperature, a solution of 4-nitrobenzylbromide (5.42 g, 25.2 mmol) in THF (40 ml) was added over 30 min. The reaction mixture was stirred for 2 h at room temperature, quenched with water and partitioned between Et₂O and water. The aqueous phase was extracted with Et₂O and the combined organic layers washed with brine, dried (MgSO₄) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM, 1:49) gave the title compound as a pale yellow oil (2.01 g): δH (CDCl₃) 8.13 (2H, d, J 8.8 Hz), 7.37 (2H, d, J 8.8 Hz), 4.23-4.06 (6H, m), 3.37-3.20 (3H, m), 1.35 (6H, t, J 7.1 Hz), 1.16 (3H, t, J 7.1 Hz): m/z (EI⁺, 70V) 360.

Intermediate 16

Ethyl 3-(4-aminophenyl)-2-(diethoxyphosphoryl)propionate

A mixture of Intermediate 15 (4.5 g, 12.0 mmol) and tin(II) chloride dihydrate (15 g) in ethanol was stirred overnight. The solvent was removed in vacuo. DCM (100 ml) and 2M NaOH (100 ml) was added and the white precipitate removed by filtration. The organic phase of the filtrate was separated and evaporated in vacuo. The residue was acidified to pH1 with dil. HCl and extracted with diethyl ether. The aqueous phase was basified to pH10 with Na₂CO₃ and extracted with EtOAc. The EtOAc extracts were dried (MgSO₄) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM 5:95) gave the title compound as a yellow oil (2.19 g): δH (CDCl₃) 6.98 (2H, d, J 8.2 Hz), 6.59 (2H, d, J 8.5 Hz), 4.22-4.04 (6H, m), 3.25-3.02 (3H, m), 1.34 (6H, m), 1.16 (3H, t, J 7.1 Hz): m/z (EI⁺, 70V) 330.

Intermediate 17

Ethyl 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(diethoxyphosphoryl)propionate

A solution of 3,5-dichloropyrid-4-ylcarbonyl chloride (1.41 g, 6.7 mmol) in THF (10 ml) was added to a solution of Intermediate 16 (2.19 g, 6.7 mmol) and NMM (0.88 ml, 8.0 mmol) in THF (40 ml). The mixture was stirred at room temperature overnight then partitioned between EtOAc and water. The aqueous layer was extracted with EtOAc and the combined organic layers washed with 10% aqueous HCl and NaHCO₃ (aq), dried (MgSO₄) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM 5:95) gave the title compound as a yellow oil (2.61 g): δH (CDCl₃) 8.55 (2H, s), 8.08 (1H, br. s), 7.55 (2H, d, J 8.5 Hz), 7.21 (2H, d, J 8.5 Hz), 4.19-4.08 (6H, m), 3.25-3.10 (3H, m), 1.35 (3H, t, J 7.1 Hz), 1.34 (3H, t, J 7.1 Hz), 1.18(3H,t, J 7.1 Hz).

Intermediate 18

Ethyl 2-[4-(3,5-dichloropyrid-4-ylcarboxamido)benzyl]acrylate

A mixture of Intermediate 17 (1.74 g, 3.6 mmol), potassium carbonate (1.48 g, 10.7 mmol) and aqueous paraformaldehyde (37% wt, 10 ml) was heated at reflux for 4 h. The mixture was partitioned between EtOAc and water. The aqueous phase was extracted with EtOAc and the combined organic layers washed with brine, dried (MgSO₄) and evaporated in vacuo. Column chromatography (silica; EtOAc/Hexane 50:50) gave the title compound as a white solid (1.09 g): δH (CDCl₃) 8.52 (1H, br. s), 8.44 (2H, br. s), 7.49 (2H, d, J 8.5 Hz), 7.18 (2H, d, J 8.5 Hz), 6.22 (1H, br. s), 5.49 (1H, br. s), 4.15 (2H, q, J 7.2 Hz), 3.60 (2H, br. s), 1.27 (3H, t, J 7.2 Hz).

Intermediate 19

Ethyl 3-amino-2-[4-(3,5-dichloropyrid-4-ylcarboxamido)benzyl]propionate

A mixture of Intermediate 18 (1.50 g, 3.7 mmol) and liquid ammonia (10 ml) was kept in a sealed vessel for 3 d at room temperature. Column chromatography (silica; MeOH/DCM 1:9 to 1:4) gave the title compound as a colourless oil (1.00 g): δH (DMSO d₆) 10.83 (1H, s), 8.78 (2H, d, J8.5 Hz), 7.54 (2H, d, J8.5 Hz), 7.16 (2H, d, J8.5 Hz), 4.00 (2H, q, J7.1 Hz), 3.29 (2H, br. s), 2.83-2.61 (5H, m), 1.10 (3H, t, J7.1 Hz): m/z (EI⁺, 70V) 396.

Intermediate 20

Ethyl 2-diazo-3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]propionate

A solution of the compound of Intermediate 3 (free amine) (2.80 g, 7.40 mmol), glacial acetic acid (1.4 ml, 24.50 mmol), isoamyl nitrite (1 ml, 7.40 mmol) in 100 ml anhydrous chloroform were stirred at reflux under nitrogen for 1 h. On cooling the solution was washed with water (2×25 ml), saturated NaHCO₃ (2×25 ml), water (2×25 ml), dried (Na₂SO₄) and evaporated in vacuo to afford the title compound as a yellow solid (2.1 g, 100%): δH (CDCl₃) 8.56 (2H, s), 7.72 (1H, br. s), 7.55 (2H, d, J8.5 Hz), 7.26 (2H, d, J8.5 Hz), 4.22 (2H, q, J, 7.1 Hz), 3.62 (2H, s), 1.25 (3H, t, J7.1 Hz).

Intermediate 21

5-Chloro-2-(2,5-dimethylpyrrol-1-yl)-pyridine

2-Amino-5-chloropyridine (10.0 g, 77 mmol), acetonyl acetone (8.8 g, 77 mmol) and a catalytic amount of p-toluenesulphonic acid in anhydrous toluene (250 ml) was heated to reflux for 5 h under Dean and Stark conditions. The solvent was removed in vacuo, the residue slurried in hexane (250 ml), filtered through celite and the solvent removed in vacuo to give the title compound as a yellow oil (16.0 g): δH (CDCl₃) 8.57 (1H, dd, J 2.7, 0.6 Hz), 7.78 (1H, dd, J 8.4, 2.7 Hz), 7.17 (1H, m, J 7.5, 0.5 Hz), 5.91 (2H, s), 2.14 (6H, s).

Intermediate 22

5-Chloro-4-propylthio-2-(2,5-dimethylpyrrol-1-yl)-pyridine

To a solution of LDA (12.3 mmol) in anhydrous toluene (6 ml) at −78° under nitrogen was added Intermediate 21 (2.3 g, 11.2 mmol) in THF (6 ml) dropwise over 15 min. After stirring a further 15 min at this temperature n-propyl disulfide (1.92, 12.8 mmol) in THF (2 ml) was added dropwise maintaining the temperature at −78°. On completion of the addition the reaction was allowed to warm to room temperature and quenched with 10% NH₄Cl solution, diluted with EtOAc (50 ml) and the phases separated. The organic phase was washed with water (2×10 ml), dried (MgSO₄) and the solvent removed in vacuo. The residue was purified by chromatography (silica; 2% EtOAc/Hexane) to give the title compound (2.9 g) as a yellow solid: δH (CDCl₃) 8.39 (1H, s), 7.00 (1H, s), 5.92 (2H, s), 2.91 (2H, d, J7.4 Hz), 2.15 (6H, s), 1.74 (2H, m), 1.09 (3H, t, J7.4 Hz).

Intermediate 23

2-Amino-6-Chloro-4-propylthiopyridine

Intermediate 22 (1.3 g, 4.6 mmol) and hydroxylamine hydrochloride (1.6 g, 23 mmol) were heated to reflux in EtOH (12 ml) and water (3.5 ml) for 16 h. The cooled solution was poured onto conc HCl (12 ml)/water (48 ml) and the resulting solid filtered, washed with water and dried to give the title compound as a brown solid (550 mg): δH (CDCl₃) 8.11 (1H, s), 6.91 (1H, s), 3.01 (2H, t, J 7.3 Hz), 1.64 (2H, m), 1.00 (3H, t, J 7.3 Hz) ): m/z (EI⁺, 70V) 203.

Intermediate 24

Resin bound (S)-2-(9-Fluorenylmethoxycarbonylamino)-3-[4-(3,5-dichloropyrid-4-yl carboxamido)phenyl]propanoic acid

Paramax Wang resin (Advanced Chemtech, 8.0 g, 0.69 mmol/g, 5.52 mmol equivalent) in DCM (100 ml) was treated with N-α-FMOC-4-nitro-L-phenylalanine (11.93 g, 27.6 mmol), diisopropylcarbodiimide (4.32 ml, 27.6 mmol) and 4-N,N-dimethylaminopyridine (0.67 g, 5.52 mmol) and mixture was agitated at room temperature for 16 h. The resin was filtered and washed with DMF, methanol and DCM, then air-dried. The resin was then treated with stannous chloride dihydrate (12.5 g, 55.2 mmol) in DMF (100 ml) at room temperature for 6 h, washed with DMF, methanol and DCM, then air dried overnight. The resin was treated with pyridine (4.44 ml, 55.2 mmol), 3,5-dichloropyrid-4-carbonyl chloride 3.52 g, 16.56 mmol) and 4-N,N-dimethylamino pyridine (0.67 g, 5.52 mmol) in DCM (100 ml). The reaction mixture was agitated at room temperature for 16 h. The resin was then washed with DMF, methanol and DCM, then with two 50 ml portions of a 10% solution of pyridine in DMF (100 ml). The resin was further washed with hot ethanol (2×100 ml), DMF, methanol and DCM then air-dried to give the title compound.

Intermediate 25

Resin bound 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-diazopropanoic acid

A portion of Intermediate 24 (3.0 g) was treated twice with a 20% solution of piperidine in DMF (100 ml), once for 5 min and once for 15 min. The resin was washed with DMF, methanol and DCM. This material was treated with isoamyl nitrite (1.79 ml, 12.30 mmols) and acetic acid (0.074 ml, 1.23 mmols) in anhydrous chloroform (70 ml) for 1 hr, then filtered and washed with DMF, methanol and DCM then finally air dried to give the title compound.

EXAMPLE 1 S-Methyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)propionate

A solution of Intermediate 4 (330 mg, 0.90 mmol), DIPEA (163μl , 121 mg, 0.94 mmol), and 2-chloro-4,6-dimethoxy-1,3,5-triazine (233 mg, 1.32 mmol) in MeOH (2 ml) was stirred under gentle reflux for 7 h under N₂. The volatiles were removed in vacuo and the residue partitioned between EtOAc (80 ml) and saturated aqueous NaHCO₃ (30 ml). The phases were separated and the aqueous layer re-extracted with EtOAc (40 ml). The combined organic extracts were washed with brine (10 ml), dried (Na₂SO₄) and evaporated in vacuo to afford a straw-coloured oil. Chromatography (silica; 4% MeOH/DCM) afforded the title compound as a colourless foam (330 mg, 73%): δH (CDCl₃) 8.46 (2H, s), 8.32 (1H, s), 7.51 (2H, d, J8.4 Hz), 7.12 (2H, d, J8.4 Hz), 6.17 (2H, d, J8.0 Hz), 5.00 (1H, d, J13.8, 6.0 Hz), 3.92 (3H, s), 3.89 (3H, s) and 3.75 (3H, s); m/z (EI⁺, 160V) 507, 509.

EXAMPLE 2 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid

A solution of the compound of Example 1 (300 mg, 0.59 mmol) and LiOH.H₂O (0.88 mmol) in dioxane (2 ml), MeOH (1 ml) and water (2 ml) was stirred at room temperature for 1 h. The pH was made acidic with a few drops of AcOH and the volatiles removed in vacuo. The residue was chromatographed [silica; DCM (400→200), MeOH (20), AcOH (3), H₂O (2)] affording the product as a colourless oil. Freeze drying from aqueous MeOH gave the title compound as a white amorphous solid (215 mg, 76%). δH (d₆ DMSO) 10.84 (1H, s), 8.77 (2H, s), 8.10 (1H, d, J8.0 Hz), 7.54 (2H, d, J 8.4 Hz), 7.29 (2H, d, J 8.4 Hz), 4.58-4.48 (1H, m), 3.80 (3H, s), 3.78 (3H, s), 3.12 (1H, dd, J14.0, 4.7 Hz) and 2.98 (1H, dd, J14, 10.2 Hz). m/z (EI⁺100V), 493, 495, 497.

EXAMPLE 3 S-Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-chloropyrimidin-4-ylamino)propionate

3,5-Dichloropyrid-4-carbonyl chloride (289 mg, 1.37 mmol) was added to a stirred solution of Intermediate 9 (400 mg, 1.25 mmol) and NMM (150 μl, 139 mg, 1.37 mmol) in dry DCM (10 ml). After stirring for 1 h at room temperature under N₂, the reaction mixture was partitioned between DCM (70 ml) and saturated aqueous NaHCO₃ (30 ml). The phases were separated and the aqueous layer re-extracted with DCM (50 ml). The combined organic extracts were washed with brine (10 ml), dried (Na₂SO₄) and evaporated in vacuo. The obtained orange oil was chromatographed (silica; 5% MeOH/DCM) to afford the title compound as a straw-coloured foam (504 mg, 82%); δH (CDCl₃,) 8.48 (2H, s), 8.41 (1H, s), 8.32 (1H, s), 7.48 (2H, d, J8.4 Hz), 7.08 (21H, d, J8.4 Hz), 6.38 (1H, s), 5.72 (1H, br s), 4.96 (1H, br s), 4.22 (2H, q, J7.1 Hz), 3.25 (1H, dd, J14.0, 5.5 Hz), 3.14 (1H, dd, J14.0, 5.8 Hz) and 1.21 (3H, t, J7.1 Hz); m/z (EI⁺, 160V) 496.

EXAMPLE 4 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-chloropyrimidin-4-ylamino)propanoic acid

A solution of Example 3 (475 mg, 0.96 mmol) and LiOH. H₂O (40 mg, 0.96 mmol) in dioxane (5 ml), MeOH (3 ml) and water (3 ml) was stirred at room temperature for 2.5 h. A few drops of AcOH were added and the volatiles removed in vacuo. The residue was chromatographed [silica; DCM (200), MeOH (20), AcOH (3), H₂O (2)] to afford the product as a slightly yellow oil. The oil was dissolved in a small volume of MeOH, diluted with water and freeze-dried to give the title compound as an off-white amorphous solid (290 mg, 65%); Found: C, 47.67; H, 2.9; N, 14.65. C₁₉H₁₄Cl₃N₅O₃.0.66 H₂O requires C, 47.67; H, 3.23; N, 14.63%. δH (d₆DMSO) 10.86 (1H, s), 8.78 (2H, s), 8.26 (1H, s), 7.98 (1H, br d, J7.6 Hz), 7.55 (2H, d, J8.2 Hz), 7.25 (2H, d, J8.2 Hz), 6.66 (1H, s), 4.76 (1H, br s), 3.16 (1H, dd, J13.9, 4.7 Hz) and 2.98 (1H, dd, J13.9, 8.9 Hz); m/z (EI⁺, 160V) 468.

EXAMPLE 5 S-Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylthiopyrimidin-4-ylamino)propionate

A solution of Intermediate 3 (2.0 g, 4.8 mmol), DIPEA (1.29 g, 1.74 ml, 10 mmol) and 4-chloro-6-propylthio-pyrimidine (1.08 g, 5.7 mmol) in 2-ethoxyethanol (8 ml) was heated at 110° for 2 days and 130° for 2 days under nitrogen. The volatiles were removed in vacuo and the dark oil partitioned between EtOAc (100 ml) and 5% aqueous citric acid (40 ml). The phases were separated and the aqueous layer re-extracted with EtOAc (2×30 ml). The combined organic extracts were washed consecutively with saturated aqueous NaHCO₃ (20 ml), water (20 ml), brine (20 ml), dried (Na₂SO₄) and treated with activated carbon, filtered and evaporated in vacuo. The obtained oil was purified by chromatography (silica; 2-3% MeOH/DCM) to afford the title compound (together with 20% of the ethoxyethyl ester analogue) as a pale yellow foam (1.26 g, 49%): δH (CDCl₃) 8.56 (2H, s), 8.38 (1H, s), 7.68 (1H, s), 7.53 (2H, d, J8.6 Hz), 7.13 (2H, d, J8.6 Hz), 6.20 (1H, s), 5.23-5.12 (1H, m), 5.00-4.84 (1H, m), 4.21 (2H, q, J7.1 Hz), 3.26 (1H, dd, J14.0, 5.3 Hz), 3.15 (1H, dd, J14.0, 5.7 Hz), 3.06 (2H, t, J7.3 Hz), 1.71 (2H, hex, J7.3 Hz), 1.29 (3H, t, J7.1 Hz), 1.04 (3H, t, J7.3Hz); m/z (EI⁺, 100V) 520.

EXAMPLE 6 S-Ethyl 3-[4(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylsulphonylpyrimidin-4-ylamino)propionate

mCPBA (assumed 60% pure, 1.43 g, 4.96 mmol) was added to a solution of the compound of Example 5 (1.26 g, 2.36 mmol) in dry DCM (20 ml), and stirred at room temperature for 4 h. 10% aqueous sodium sulphite (20 ml) was added and stirred for 5 min. After diluting with DCM (130 ml) and shaking, the phases were separated. The organic phase was washed consecutively with saturated aqueous NaHCO₃ (3×30 ml), water (25 ml) and brine (10 ml), dried (Na₂SO₄) and evaporated in vacuo. Chromatography (silica; 2% MeOH/DCM) afforded the title compound as a pale yellow foam (640 mg, 50%): δH (CDCl₃) 8.63 (1H, s), 8.50 (2H, s), 8.05 (1H, s), 7.47 (2H, d, J8.6 Hz), 7.10 (2H, d, J8.6 Hz), 6.22-6.13 (1H, br. m), 5.18-5.08 (1H, br. m), 4.24 (2H, q, J7.4Hz), 3.32-3.25 (2H, m), 3.17 (1H, dd, J14.1, 6.2 Hz), 1.75 (2H, hex, J7.4 Hz), 1.31 (3H, t, J7.1 Hz), 1.03 (3H, t, J7.4 Hz); m/z (EI⁺, 100V) 566.

EXAMPLE 7 S-3-[14-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylsulphonylpyrimidin-4-ylamino)propanoic acid

The title compound (395 mg, 66%) was prepared from the compound of Example 6 (630 mg, 1.11 mmol) by hydrolysis in a similar manner to Example 2: δH (DMSO d₆) 10.85 (1H, s), 8.77 (2H, s), 8.56 (1H, s), 8.44 (1H, d, J7.8 Hz), 7.55 (2H, d, J8.4 Hz), 7.26 (2H, d, J8.4 Hz), 7.22 (1H, s), 4.85-4.72 (1H, br. m), 3.33 (2H, t, J7.6 Hz), 3.18 (1H, dd, J13.8, 4.7 Hz), 2.99 (1H, dd, J13.8, 9.1 Hz), 1.59 (2H, hex, J7.6 Hz), 0.93 (3H, t, J7.6 Hz); m/z (E⁺, 70V) 538.

EXAMPLE 8 S-Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylsulphinylpyrimidin-4-ylamino)propionate

mCPBA (assumed 86% pure, 223 mg, 1.11 mmol) was added to an ice-bath cooled solution of the compound of Example 5 (500 mg, 0.94 mmol) in dry DCM (15 ml), and stirred for 1 h with cooling and for 2 h at room temperature. 10% aqueous sodium sulphite (10 ml) and DCM (100 ml) was added and the mixture vigorously stirred for 5 min. The phases were separated and the organic phase was washed consecutively with saturated aqueous NaHCO₃ (2×30ml), water (10 ml) and brine (10 ml), dried (Na₂SO₄) and evaporated in vacuo. Chromatography (silica; 2-3% MeOH/DCM) afforded the title compound as a mixture of diastereoisomers together with a small amount of the corresponding ethoxyethyl analogue (330 mg, 64%): δH (CDCl₃) 8.82-8.80 (1H, s), 8.49-8.45 (3H, s), 7.53-7.47 (2H, overlapping d's, J8.6 Hz), 7.17-7.08 (2H, overlapping d's J8.6 Hz), 7.01-6.95 (1H, s), 6.31-6.22 (1H, m), 5.20 5.00 (1H, br. m), 4.30-4.15 (2H, overlapping q's, J7 Hz), 3.87-3.12 (2H, br. m), 3.10-3.01 (1H, br. m), 2.87-2.70 (1H, br. m), 1.92-1.74 (1H, br. m), 1.69-1.50 (1H, br. m), 1.33-1.20 (3H, t, J7 Hz), 1.08-0.99 (3H, overlapping t's, J7Hz); m/z (EI⁺, 70V) 550.

EXAMPLE 9 S-3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylsulphinylpyrimidin-4-ylamino)propanoic acid

The title compound as a 1:1 mixture of diastereoisomers (278 mg, 92%) was prepared from the compound of Example 8 (320 mg, 0.58 mmol) by hydrolysis in a similar manner to Example 2;δH (DMSO d₆) 10.85 (1H, s), 8.77 (2H, s), 8.40 (1H, s), 8.25 (1H, d, J7.6 Hz), 7.55 (2H, d, J8.3 Hz), 7.30-7.20 (2H, m), 7.09 (1H, s), 4.82-4.69 (1H, m), 3.17 (1H, dd, J14, 4 Hz), 3.12-2.90 (2H, br. m), 2.85-2.72 (1H, m), 1.80-1.62 (1H, m), 1.55-1.37 (1H, m), 1.01-0.90 (3H,overlapping t's); m/z (EI⁺,70V) 522.

EXAMPLE 10 S-Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-benzylthiopyrimidin-4-ylamino)propionate

A solution of Intermediate 3 (1.0 g, 2.39 mmol), DIPEA (647 mg, 872 μl, 5 mmol) and 4-benzylthio-6-chloro-pyrimidine (678 mg, 2.87 mmol) in 2-ethoxyethanol (4 ml) was heated at 120° for 58 h. The volatiles were removed in vacuo and the residue worked up in a manner analogous to that described for Example 5. The crude product was chromatographed (silica; 2-3% MeOH/DCM) to afford the title compound (together with some of the ethoxyethyl ester analogue) as a near colourless glassy solid (560 mg, 40%): δH (CDCl₃) 8.55 (2H, s), 8.42 (1H, s), 7.73 (1H, s), 7.51 (2H, d, J8.4 Hz), 7.39-7.24 (m, 5H), 7.11 (2H, d, J8.4 Hz), 6.19 (1H, s), 5.27-5.18 (1H, m), 4.95-4.81 (1H, m), 4.37 (2H, s), 4.21 (2H, q, J7.1 Hz), 3.21 (1H, dd, J14.0, 5.0Hz), 3.15 (1H, dd, J14.0, 5.7 Hz), 1.28 (3H, t, J7.1 Hz), m/z (EI⁺, 70V) 582.

EXAMPLE 11 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-benzylthiopyrimidin-4-ylamino)propanoic acid

The title compound was prepared from the compound of Example 10 by hydrolysis in a similar manner to Example 2: δH (DMSO d₆, 390K) 10.84 (1H, br. s), 8.77 (2H, s), 8.24 (1H, s), 7.55-7.25 (7H, m), 6.46 (1H, s), 4.66 (1H, m), 4.31 (2H, s), 3.13-2.90 (2H, m); m/z (EI⁺, 70V) 554.

EXAMPLE 12 S-Ethyl 3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propionate and S-Ethyl 3-[3,5-dichloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propionate

Chlorine gas was bubbled through a vigorously stirred ice-bath cooled mixture of the compound of Example 10 (550 mg), DCM (8 ml) and 10% aqueous HCl (20 ml). The cooled reaction mixture was then stirred for an additional 30 min. Excess chlorine was removed by purging with nitrogen and the reaction mixture diluted with DCM (70 ml). The phases were shaken, separated and the aqueous phase re-extracted with DCM (30 ml). The combined organic extracts were treated with diethylamine (2 ml) and left to stand for 45 min. The volatiles were removed in vacuo and the residue partitioned between EtOAc (70 ml) and water (20 ml). The phases were separated and the aqueous phase re-extracted with EtOAc (2×15 ml). The combined organic extracts were washed with brine (10 ml), dried (MgSO₄) and evaporated in vacuo. The obtained dark foam was chromatographed twice (silica; 2% MeOH/DCM then 25%Et₂O/DCM) affording a 2:1 mixture of the title compounds (240 mg): δH (CDCl₃) 8.62 (1H, s), 8.59 (2H×0.66, s), 8.57 (2H×0.33, s), 8.31 (1H×0.66, s), 7.85 (1H×0.33, s), 7.20 (2H×0.33, s), 7.11 (1H×0.66, d, J8.4 Hz), 5.84-5.72 (1H, br. m), 5.18-4.95 (1H, br. m), 4.26 (2H, q, J7.1 Hz), 3.39 (2H, q, J7.1 Hz), 3.28 (1H, dd, J14.0, 5.3 Hz), 3.17 (1H, dd, J14.0, 5.6 Hz), 1.32 (3H ×0.33, t, J7.1 Hz), 1.30 (3H×0.66, t, J7.1 Hz), 1.17 (6H, t, J7.1 Hz); m/z (EI⁺, 70V) 531 and 665.

EXAMPLE 13 S-3-[3-Chloro-4-(3,6-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid and S-3[-3,5-dichloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid

The mixture of compounds of Example 12 (240 mg, 0.38 mmol) was treated with a solution of LiOH.2H₂O (27 mg, 0.64 mmol) in dioxan (3 ml) and water (3 ml) at room temperature for 2.5 h. A few drops of acetic acid were added and the volatiles were removed in vacuo. The residue was chromatographed several times (silica; DCM (400-200), MeOH (20), AcOH (3), H₂O (2)) to separate the two title compounds, affording after freeze-drying from aqueous methanol, the less polar S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-diethylaminosulphonyl pyrimidin-4-ylamino)propanoic acid as a white amorphous solid (105 mg, 49%): δH (DMSO d₆) 10.61 (1H, s), 8.75 (2H, s), 8.50 (1H, s), 8.31 (1H, d, J 7.8 Hz), 7.62 (1H, d, J 8.1 Hz), 7.43 (1H, s), 7.28 (1H, d, J8.1 Hz), 7.10 (1H, s), 4.83-4.75 (1H, m), 3.26 (4H, t, J7.1 Hz), 3.22 (1H, m), 3.05 (1H, dd, J13.8, 9.1 Hz), 1.05 (6H, t, J7.1 Hz); m/z (ES⁺, 70V) 603; and the more polar S-3-[3,5-dichloro-4-(3,5-dichloropyrid4-ylcarboxamido) -phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid as a white amorphous solid (49 mg, 21%): δH (DMSO d₆) 10.83 (1H, s), 8.76 (2H, s), 8.50 (1H, s), 8.29 (1H, d, J 7.8 Hz), 7.44 (2H, s), 7.12 (1H, s), 4.85-4.74 (1H, m), 3.26 (4H, t, J7.1 Hz), 3.20 (1H, m), 3.05 (1H, dd, J13.8, 9.9 Hz), 1.05 (6H, t, J7.1 Hz); m/z (EI⁺, 70V) 637.

EXAMPLE 14 S-Ethyl 3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propionate

The title compound (430 mg) was prepared in an analogous manner to the compound of Example 12 starting from the compound of Example 10 (500 mg) and using n-propylamine: δH (CDCl₃) 8.63 (1H, s), 8.60 (2H, s), 8.45 (1H, s), 8.32 (1H, d, J7.8 Hz), 7.88 (1H, s), 7.25-6.98 (3H ,m), 6.02-5.90 (1H, m), 5.13-5.06 (1H, m), 4.28 (2H, q, J7.1 Hz), 3.38-3.15 (2H, m), 3.04 (2H, q, J7.1 Hz), 1.53 (2H, q, J7.1 Hz), 1.24 (3H, t, J7.1 Hz), 0.97 (3H, t, J7.1 Hz); m/z (EI⁺, 70V) 627.

EXAMPLE 15 S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propanoic acid

The title compound (151 mg, 66%) was prepared from the compound of Example 14 (394 mg, 0.60 mmol) by hydrolysis in a similar manner to Example 2: δH (DMSO d₆) 10.61 (1H, s), 8.76 (2H, s), 8.51 (1H, s), 8.32 (1 H, d, J7.8 Hz), 7.80 (1H, t, J5.7 Hz), 7.63 (1H, d, J8.3 Hz 7.45 (1 H, s), 7.29 (1H, d, J8.3 Hz), 7.10 (1H, s), 4.85-4.74 (1H, m), 3.22 (1H, dd, J13.9, 4.9 Hz), 3.02 (1H, dd, J13.9, 9.0 Hz), 2.86 (2H, t, J6.8 Hz), 1.38 (2H, hex, J6.8 Hz), 0.79 (3H, t, J7.3 Hz); m/z (EI⁺, 70V) 589.

EXAMPLE 16 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-methoxy-2-methylsulphonylpyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2,4-di-(methylsulphonyl)-6-methoxypyrimidine by a method similar to that described for Intermediate 10 followed by ester hydrolysis according to the method of Example 2: δH (DMSO d₆) 12.70 (1H, br. s), 10.84 (1H, s), 8.77 (2H, s), 8.23 (d, J7.6 Hz) and 8.08 (d, J7.7 Hz) together (1H), 7.54 (2H, d, J8.0 Hz), 7.33 (2H, d, J8.0 Hz), 6.48 (1H, s), 4.55-4.46 (1H, m), 3.89 (s) and 3.86 (s) together (3H), 3.20-3.03 (2H, m); m/z (EI⁺, 70V) 540.

EXAMPLE 17 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-methoxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2,4-di-n-propylsulphonyl-6-methoxypyrimidine by a method similar to that described for Intermediate 10 followed by ester hydrolysis according to the method of Example 2: δH (DMSO d₆) 12.69 (1H, br.s), 10.83 (1H, s), 8.77 (2H, s), 8.18 (d, J7.9 Hz) and 8.06 (d, J7.9 Hz) together (1H), 7.54 (2H, d, J8.2 Hz), 7.32 (2H, d, J8.2 Hz), 6.48 (s) and 6.47 (s) together (1H), 4.55-4.42 (1H, m), 3.89 (s) and 3.86 (s) together (3H), 3.29 (2H, q, J7.7 Hz), 3.12 (1H, dd, J13.9, 4.6 Hz), 3.02 (1H, dd, J13.9, 9.9 Hz), 1.68-1.49 (2H, m), 0.94 (t, J7.2 Hz) and 0.92 (t, J7.2 Hz) together (3H); m/z (EI⁺, 70V) 568 and 570.

EXAMPLE 18 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-trifluoromethylpyrimidin-2-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2-chloro-4-(trifluoromethyl)pyrimidine, followed by hydrolysis: δH (DMSO d₆) 12.70 (1H, br.s), 10.83 (1H, s), 8.77 (2H, s), 8.58 (1H, d, J 4.9 Hz), 8.15 (d, J 8.0 Hz) and 8.06 (d, J 8.0 Hz) together (1H), 7.54 (2H, d, J 8.2 Hz), 7.33 (2H, d, J 8.2 Hz), 6.99 (1H, d, J 4.9 Hz), 4.62-4.42 (1H, br. m), 3.15 (1H, dd, J 13.7, 4.4 Hz), 3.10-2.95 (1H, m); m/z (EI⁺, 60V) 500 and 502.

EXAMPLE 19 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-phenoxypyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 4-chloro-6-phenoxypyrimidine, followed by hydrolysis: δH (DMSO d₆) 10.85 (1H, s), 8.77 (2H, s), 8.12 (1H, s), 7.60 (1H, br. d, J 8.0 Hz), 7.54 (2H, d, J 8.3 Hz), 7.41 (2H, t, J 7.8 Hz), 7.27-7.20 (3H, m), 7.12 (2H, d, J 8.2 Hz), 5.88 (1H, s), 4.80-4.60 (1H, br. m), 3.12 (1H, dd, J 13.8, 4.7 Hz), 2.90 (1H, dd, J 13.8, 9.5 Hz); m/z (EI⁺, 60V) 524 and 526.

EXAMPLE 20 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(2-methylthiopyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 4-chloro-2-methylthiopyrimidine followed by hydrolysis: δH (DMSO d₆) 10.83 (1H, s), 8.77 (2H, s), 7.85 (1H, d, J 5.7 Hz), 7.71 (1H, br. s), 7.54 (1H, d, J 8.5 Hz), 7.25 (1H, d, J 8.5 Hz), 6.28 (1H, d, J 5.7 Hz), 4.70-4.53 (1H, br. m), 3.12 (1H, dd, J 14.0, 8.0 Hz), 2.96 (1H, dd, J 14.0, 8.0 Hz); m/z (EI⁺, 60V) 478.

EXAMPLE 21 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(5-carboxy-2-methylthiopyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and ethyl 4-chloro-2-methylthiopyrimidine-5-carboxylate, followed by hydrolysis: δH (DMSO d₆) 10.87 (1H, s), 9.01 (1H br. s), 8.77 (2H, s), 8.49 (1H, s), 7.55 (2H, d, J 8.4 Hz), 7.20 (2H, d, J 8.4 Hz), 4.90-4.80 (1H, m), 3.21 (1H, dd, J 13.8, 5.2 Hz), 3.09 (1H, dd, J 13.8, 6.9 Hz), 2.44 (3H, s); m/z (EI⁺, 60V) 522.

EXAMPLE 22 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(5-ethoxycarboxy-2-methylthiopyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and ethyl 4-chloro-2-methylthiopyrimidine-5-carboxylate with subsequent partial hydrolysis of the coupled product: δH (DMSO d₆) 10.84 (1H, br. s), 8.77 (2H, s), 8.55 (1H, s), 8.47 (1H, d, J 6.8 Hz), 7.54 (2H, d, J 8.3 Hz), 7.18 (2H, d, J 8.3 Hz), 4.94-4.83 (1H, m), 4.25 (2H, q, J 7.1 Hz), 3.25 (1H, dd, J 13.8, 5.3 Hz), 3.13 (1H, dd, J 13.8, 6.8 Hz), 2.46 (3H, s), 1.26 (3H, t, J 7.1 Hz); m/z (EI⁺, 60V) 550.

EXAMPLE 23 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(3-nitropyrid-2ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2-chloro-3-nitropyridine, followed by hydrolysis: δH (DMSO d₆) 10.86 (1H, s), 8.77 (2H, s), 8.49-8.43 (2H, m), 8.29 (1H, d, J 7.0 Hz), 7.55 (2H, d, J 8.5 Hz), 7.22 (2H, d, J 8.5 Hz), 6.84 (1H, dd, J 8.3, 4.5 Hz), 5.03-4.99 (1H, m), 3.30-3.15 (2H, m); m/z (EI⁺, 60V) 476 and 478.

EXAMPLE 24 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(5-nitropyrid-2-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2-chloro-5-nitropyridine, followed by hydrolysis: δH (DMSO d₆) 10.84 (1H, s), 8.85 (1H, d, J 2.6 Hz), 8.76 (2H, s), 8.32 (1H, d, J 7.4 Hz), 8.10 (1H, dd, J 9.4, 2.6 Hz), 7.54 (2H, d, J 8.3 Hz), 7.26 (2H, d, J 8.3 Hz), 6.69 (1H, d, J 9.4 Hz), 4.81 (1H, br. m), 3.19 (1H, dd, J 13.9, 4.7 Hz), 3.00 (1H, dd, J 13.9, 9.2 Hz); m/z (EI⁺, 60V) 476 and 478.

EXAMPLE 25 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-propylthiopyrimidin-4-ylamino)propanoic acid

The title compound was prepared by hydrolysis of the compound of Example 5: δH (DMSO d₆) 10.83 (1H, br. s), 8.77 (2H, s), 8.21 (1H, s), 7.54 (2H, d, J 8.4 Hz), 7.24 (2H, d, J 8.4 Hz), 6.43 (1H, br. s), 4.67 (1H, br. s), 3.13 (1H, dd, J 13.9, 4.8 Hz)), 3.00-2.90 (3H, m), 1.61 (2H, hex, J 7.3 Hz), 0.95 (3H, t, J 7.3 Hz); m/z (EI⁺, 160V) 506 and 508.

EXAMPLE 26 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(2-nitrophenylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2-fluoronitrobenzene, followed by hydrolysis: δH (DMSO d₆) 10.86 (1H, br. s), 8.76 (2H, s), 8.20 (1H, d, J 7.7 Hz), 8.08 (1H, dd, J 8.6, 1.6 Hz), 7.56 (2H, d, J 8.5 Hz), 7.53 (1H, m), 7.16 (2H, d, J 8.5 Hz), 7.04 (1H, d, J 8.2 Hz), 6.74 (1H, t, J 7.5 Hz), 4.79-4.73 (1H, m), 3.26-3.13 (2H, m); m/z (EI⁺, 60V) 476 and 478.

EXAMPLE 27 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(pyrimidin-2-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2-chloropyrimidine, followed by hydrolysis: δH (DMSO d₆) 10.82 (1H, br. s), 8.76 (2H, s), 8.23 (2H, d, J 4.7 Hz), 7.52 (2H, d, J 8.3 Hz), 7.27 (2H, d, J 8.3 Hz), 7.12 (1H, d, J 7.5 Hz), 6.57 (1H, t, J 4.7 Hz), 4.50-4.40 (1H, m), 3.12 (1H, dd, J 13.8, 4.5 Hz), 3.00 (1H, dd, J 13.8, 9.1 Hz); m/z (EI⁺, 60V) 432 and 434.

EXAMPLE 28 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-methylsulphonylpyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and 2,4-di-(methylsulphonyl)-pyrimidine, followed by hydrolysis: δH (DMSO d₆) 8.79 (2H, s), 8.58 (1H, s), 8.47 (1H, d, J 7.8 Hz), 7.57 (2H, d, J 8.5 Hz), 7.28 (2H, d, J 8.5 Hz), 7.21 (1H, s), 4.79 (1H, m), 3.20 (3H, s), 3.19 (1H, m), 3.00 (1H, dd, J 13.9, 9.2 Hz); m/z (EI⁺, 70V) 510.

EXAMPLE 29 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(2-propylsulphonylpyrimidin-4-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and Intermediate 13, followed by hydrolysis: δH (DMSO d₆) 8.60 (2H, s), 8.10 (1H, d, J 6.0 Hz), 7.50 (2H, d, J 8.5 Hz), 7.28 (2H, d, J 8.5 Hz), 6.70 (1H, d, J 6.0 Hz), 4.90 (1H, m), 3.30 (4H, m), 3.10 (1H, m), 1.20 (2H, m), 1.00 (3H, t, J 7.1 Hz); m/z (EI⁺, 70V) 538.

EXAMPLE 30 S-Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-dimethylamino-1,3,5-triazin-2-ylamino)propionate

To a solution of Intermediate 10 (0.26 g, 0.50 mmol) in dry THF (5 ml) under nitrogen was added dimethylamine (941 mg, 0.5 mmol) and DIPEA (0.17 ml). The solution was stirred at room temperature for 4.5 h then the solvent was removed in vacuo and DCM (10 ml) was added. The organic layer was washed with aqueous sodium bicarbonate and water, dried (MgSO₄) and the solvent removed in vacuo. Flash chromatography (silica; EtOAc/Hexane 1:1) gave the title compound as a froth (0.16 g, 59%): δH (CDCl₃) 8.55 (2H, s), 7.75 (1H, br. s), 7.54 (2H, d, J 8.4 Hz), 7.18 (2H, d, J 8.4 Hz), 5.40 (1H, m), 4.90 (1H, m), 4.17 (2H, d, J 7.2 Hz), 3.84 (3H, s), 3.28-3.10 (2H, m), 3.11 (6H, s), 1.16 (3H, t, J 7.2 Hz); m/z (EI⁺, 70V) 534.

EXAMPLE 31 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-dimethylamino-1,3,5-triazin-2-ylamino)propanoic acid

The title compound was prepared from the compound of Example 30 by hydrolysis in a similar manner to Example 2: δH (DMSO d₆) 10.83 (1H, s), 8.77 (2H, s), 7.53 (2H, d, J 8.0 Hz), 7.38 (1H, m), 7.28 (2H, d, J 7.9 Hz), 4.72 (1H, m), 3.72 (3H, d, J 4.2 Hz), 3.00 (8H, d, J 4.5 Hz); m/z (EI⁺, 60V) 506.

In a similar manner were prepared the following compounds of Examples 32-49

EXAMPLE 32 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-diethylamino-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and diethylamine, followed by hydrolysis: δH (DMSO d₆, 390K) 10.39 (1H, br. s), 8.65 (2H, s), 7.50 (2H, d, J 8.3 Hz), 7.25 (2H, d, J 8.3 Hz), 6.41 (1H, br. m), 4.55 (1H, br. m), 3,54 (4H, dd, J 6.9 Hz), 3.39 (3H, s), 3.20-3.00 (2H, m), 1.11 (6H, t, J 6.9 Hz); m/z (EI⁺, 60V) 534.

EXAMPLE 33 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-morpholino-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and morpholine, followed by hydrolysis: δH (DMSO d₆, 365K) 10.49 (1H, br. s), 8.69 (2H, s), 7.53 (2H, d, J 8.1 Hz), 7.25 (2H, d, J 8.4 Hz), 6.87 (1H, br. s), 4.62 (1H, m), 3.78 (3H, s), 3.70-3.55 (8H, m), 3.20-3.00 (2H, m); m/z (EI⁺, 70V) 548.

EXAMPLE 34 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-propyloxy-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and sodium n-propoxide, followed by hydrolysis: δH (DMSO d₆, 390K) 8.69 (2H, s), 7.53 (2H, d, J 8.4 Hz), 7.50 (1H, br. m), 7.27 (2H, d, J 8.3 Hz), 4.66 (1H, m), 4.20 (2H, t, J 6.6 Hz), 3.82 (3H, s), 3.25-3.00 (2H, m), 1.68 (2H, m, J 6.8 Hz), 0.93 (3H, t, J 7.4 Hz); m/z (EI⁺, 60V) 521.

EXAMPLE 35 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-phenoxy-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and sodium phenoxide, followed by hydrolysis: δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 8.25 (1H, m), 7.53 (2H, d, J 8.4 Hz), 7.40-7.10 (7H, m), 4.52 (1H, m), 4.41 (1H, m), 3.76 (3H, s), 3.10-2.80 (2H, m), m/z (EI⁺, 60V) 555.

EXAMPLE 36 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-n-propylamino-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and n-propylamine, followed by hydrolysis: δH (DMSO d₆, 390K) 10.38 (1H, br. s), 8.67 (2H, s), 7.51 (2H, d, J 8.4 Hz), 7.25 (2H, d, J 8.4 Hz), 6.60 (1H, m), 6.44 (1H, m), 4.68 (1H, m), 3.77 (3H, s), 3.25-3.00 (4H, m), 1.53 (2H, q, J 14.3, 7.2 Hz), 0.88 (3H, t, J 7.4 Hz); m/z (EI⁺, 60V) 520.

EXAMPLE 37 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-[4-methoxy-6-(2-hydroxyethylamino)-1,3,5-triazin-2-ylamino]propanoic acid

Prepared from Intermediate 10 and 2-hydroxyethylamine, followed by hydrolysis: δH (DMSO d₆, 350K) 10.57 (1H, s), 8.72 (2H, s), 7.54 (2H, d, J 8.2 Hz), 7.27 (2H, d, J 8.3 Hz), 6.78-6.68 (1H, m), 4.62 (1H, m), 3.77 (3H, s), 3,50 (2H, d. J 6.0 Hz), 3.35 (2H, d, J 5.65 Hz), 3.17-3.02 (2H, m); m/z (EI⁺, 60V) 522.

EXAMPLE 38 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-(4-carboxylpiperidinyl)-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and ethyl piperidine-4-carboxylate, followed by hydrolysis: δH (DMSO d₆, 390K) 10.83 (1H, s), 8.76 (1H, s), 7.53 (2H, d, J 8.3 Hz), 7.45 (1H, m), 7.27 (2H, d, J 8.4 Hz), 4.55-4.30 (2H, m), 3.72 (3H, s), 3.10-2.80 (2H, m), 1.90-1.75 (2H, m), 1.50-1.30 (2H, m); m/z (EI⁺, 70V) 590.

EXAMPLE 39 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-piperazinyl-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and N-BOC piperazine, followed by hydrolysis and BOC deprotection: δH (DMSO d₆) 10.58 (1H, s), 8.72 (3H, s), 7.53 (2H, d, J 8.5 Hz), 7.24 (2H, d, J 8.5 Hz), 6.86 (1H, m), 4.56 (1H, m), 3.78 (3H, s), 3.64 (4H, t, J 5.0 Hz), 3.17-3.00 (2H, m), 2.75 (4H, t, J 5.0 Hz); m/z (EI⁺, 60V) 547.

EXAMPLE 40 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4-methoxy-6-(N′-t-butyloxycarbonylpiperazinyl)-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 10 and N-BOC piperazine, followed by hydrolysis: δH (DMSO d₆, 390K) 10.34 (1H, s), 8.67 (2H, s), 7.53 (2H, d, J 7.0 Hz), 7.52 (1H, m), 7.27 (2H, d, J 8.4 Hz), 6.65 (1H, d, J 7.6 Hz), 4.70 (1H, m), 3.81 (3H, s), 3.70 (4H, m), 3.40 (4H, m), 3.30-3.10 (2H, m), 1.46 (9H, s); m/z (EI⁺, 70V) 647.

EXAMPLE 41 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-methyl-2-propyisulphonylpyrimidin-4-ylamino)propanoic acid

Prepared from Intermediate 3 and 6-methyl-2,4-di-(n-propylsulphonyl)-pyrimidine, followed by hydrolysis: δH (DMSO d₆) 10.83 (1H, s), 8.77 (2H, s), 8.27 (1H, d, J 8.0 Hz), 7.54 (2H, d, J 8.3 Hz), 7.25 (2H, d, J 8.2 Hz), 6.58 (1H, s), 4.66 (1H, m), 3.44-2.90 (4H, m), 2.28 (3H, s), 1.67-1.59 (2H, m), 0.96 (3H, t, J 7.4 Hz); m/z (EI⁺, 70V) 552.

EXAMPLE 42 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-benzylsulphonylpyrimidin-4-ylamino)propanoic acid

Prepared from Intermediate 3 and 4,6-di-(benzylsulphonyl)pyrimidine, followed by hydrolysis: δH (DMSO d₆) 10.85 (1H, s), 8.77 (2H, s), 8.62 (1H, s), 8.35 (1H, d, J 7.4 Hz), 7.54 (2H, d, J 8.3 Hz), 7.30-7.19 (7H, m), 7.02 (1H, s), 4.71 (1H, m), 3.29-2.97 (2H, m), 1.89 (2H, s); m/z (EI⁺, 70V) 586.

EXAMPLE 43 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-carboxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid

Prepared from Intermediate 3 and methyl 2,6-di-(n-propylsulphonyl)pyrimidine-4-carboxylate, followed by hydrolysis: δH (DMSO d₆) 10.85 (1H, s), 8.76 (1H, s), 8.76 (2H, s), 7.56 (2H, d, J 8.5 Hz), 7.35 (1H, s), 7.26 (2H, d, J 8.5 Hz), 4.74 (1H, m), 3.74-2.98 (4H, m), 1.70-1.62 (2H, q, J 7.5 Hz), 0.97 (3H, t, J 7.4 Hz); m/z (EI⁺, 70V) 582.

EXAMPLE 44 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-methyl-4-(propylaminocarbonyl)-pyrimidin-2-ylamino)propanoic acid

Prepared from Intermediate 3 and 2-chloro-4-methyl-6-(n-propylamino-carbonyl) pyrimidine, followed by hydrolysis: δH (DMSO d₆) 10.82 (1H, s), 8.76 (2H, s), 8.32 (1H, br. s), 7.53 (2H, d, J 8.5 Hz), 7.31 (2H, d, J 8.2 Hz), 7.00 (1H, s), 4.75 (1H, m), 3.30-3.10 (4H, m), 2.30 (3H, s), 1.54-1.47 (2H, q, J 14.6, 7.4 Hz), 0.87 (3H, t, J 7.3 Hz); m/z (EI⁺, 70V) 531.

EXAMPLE 45 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-[6-methyl -4-(diethylaminocarbonyl)-pyrimidin-2-ylamino]propanoic acid

Prepared from Intermediate 3 and 2-chloro-4-methyl-6-(diethylaminocarbonyl) pyrimidine, followed by hydrolysis: δH (DMSO d₆) 10.34 (1H, s), 8.67 (1H, s), 7.51 (2H, d, J 6.3 Hz), 7.27 (2H, d, J 8.3 Hz), 6.54 (1H and 1H, together 2H, s), 4.75 (1H, m), 3.35 (4H, m), 3.23-3.07 (2H, m), 2.30 (3H, s), 1.13 (6H, m); m/z (EI⁺, 70V) 545.

EXAMPLE 46 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-carboxy-2-iso-butylsulphonylpyrimidin-4-ylamino)propanoic acid

Prepared from Intermediate 3 and methyl 2,6-di-(iso-butylsulphonyl)pyrimidine-4-carboxylate, followed by hydrolysis: δH (DMSO d₆) 10.84 (1H, s), 8.76 (2H, s), 7.55 (2H, d, J 8.5 Hz), 7.35 (1H, s), 7.26 (2H, d, J 8.5 Hz), 4.75 (1H, m), 3.39-3.02 (4H, m), 2.14-2.07 (1H, m), 0.98 (6H, d, J 3.3 Hz);

m/z (EI⁺, 70V) 596.

EXAMPLE 47 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(6-carboxy-2-hexylsulphonylpyrimidin-4-ylamino)propanoic acid

Prepared from Intermediate 3 and methyl 2,6-di-(n-hexylsulphonyl)pyrimidine-4-carboxylate, followed by hydrolysis: δH (DMSO d₆) 10.84 (1H, s), 8.78 (2H, s), 7.54 (2H, d, J 8.4 Hz), 7.36 (1H, s), 7.25 (2H, d, J 8.5 Hz), 4.77-4.71 (1H, m), 3.40-3.00 (4H, m), 1.65 (2H, m), 1.36 (2H, m), 1.24 (2H, t, J 3.3 Hz), 0.82 (3H, t, J 6.9 Hz); m/z (EI⁺, 70V) 624.

EXAMPLE 48 S-3-[4-(3,5-Dichloropyrid-4-ylmethyloxy)-phenyl]-2-(4.6-dimethox-1,3,5-triazin-2-ylamino)propanoic acid

The title compound was prepared from Intermediate 7 and 2-chloro-4,6-dimethoxy-1,3,5-triazine, followed by hydrolysis: δH (DMSO d₆) 8.7o (2H, s), 8.10 (1H, d, J 8.0 Hz), 7.24 (2H, d, J 8.3 Hz), 6.95 (2H, d, J 8.3 Hz), 5.18 (2H, s), 4.52 (1H, m), 3.81 (3H, s), 3.80(3H, s), 3.15-2.90 (2H, m); m/z (EI⁺, 60V) 480.

EXAMPLE 49 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(4.6-propyloxy-1,3,5-triazin-2-ylamino)propanoic acid

Prepared from Intermediate 3 and 2-chloro-4,6-di-n-propoxy-1,3,5-triazine, followed by hydrolysis: δH (DMSO d₆) 10.84 (1H, br. s), 8.77 (2H, s), 8.00 (1H, d, J 7.8 Hz), 7.54 (2H, d, J 8.4 Hz), 7.30 (2H, d, J 8.4 Hz), 4.52 (1H, m), 3.15-2.80 (2H, m), 1.64 (4H, m), 0.89 (6H, m); m/z (EI⁺, 60V) 549.

EXAMPLE 50 S-Methyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(N-methyl-4,6-dimethoxy-1,3,5-triazin-2-ylamino)propionate

The title compound (350 mg, 80%) was prepared in an analogous manner to the compound of Example 1 starting from S-Methyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(N-methylamino)propionate hydrochloride (500 mg 1.19 mmol): δH (CDCl₃) 8.55 (2H, s), 7.80 (1H, s), 7.50 (2H, d, J 8.0 Hz), 7.20 (2H, d, J 8.0 Hz), 5.40 (1H, m), 4.00 (3H, s), 3.95 (3H, s), 3.75 (3H, s) 3.50 (2H, m), 3.10 (3H, s); m/z (EI⁺, 70V) 521.

EXAMPLE 51 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-(N-methyl-4,6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid

The title compound was prepared from the compound of Example 50 by the method of Example 2: δH (DMSO d₆) 10.81 (s, 1H), 8.77 (2H, s), 7.51 (2H, d, J 8.5 Hz), 7.23 (2H, d, J 8.5 Hz), 5.34 (1H, m), 3.81 (3H, s), 3.80 (3H, s), 3.22 (2H, m), 2.92 (3H, s); m/z (EI⁺, 70V) 507.

EXAMPLE 52 R-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)-phenyl]-2-( 4.6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid

The title compound was prepared from R-ethyl-3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl-2-aminopropionate hydrochloride in an analogous fashion to the compounds of Examples 1 and 2: δH (DMSO d₆) 10.84 (s, 1H), 8.72 (2H, s), 8.15 (1H, d, J 7.8 Hz), 7.55 (2H, d, J 8.4 Hz), 7.30 (2H, d, J 8.4 Hz), 4.55 (1H, m), 3.80 (3H, s), 3.78 (3H, s), 3.12 (1H, dd, J 13.8, 4.5 Hz), 3.01 (1H, dd, J 13.8, 10.3 Hz)); m/z (EI⁺, 70V) 493.

EXAMPLE 53 S-Ethyl 3-[4-N-methyl-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(N-methyl-4,6-dimethoxy-1,3,5-triazin-2-ylamino)propionate

To a solution of the ethyl ester analogue of the compound of Example 50 (310 mg, 0.59 mmol) in DMF (10 ml) was added cesium carbonate (388 mg, 1.18 mmol) and iodomethane (390 μl, 590 mmol) and the mixture was stirred at room temperature for 16 h. The reaction was concentrated in vacuo and extracted with ethyl acetate (50 ml). The organics were washed with water (2×50 ml), dried (Na₂SO₄) and evaporated. The residue was chromatographed (silica; EtOAc/Hexane 1:1) to give the title compound as a white solid (100 mg, 31%): δH (CDCl₃) 8.35 (1H, d), 7.20 (2H, d), 7.00 (2H, d), 5.10 (1H, m), 4.10 (2H, m), 4.00 (3H, s), 3.90 (3H, s), 3.49 (3H, s) 3.40 (1H, m), 3.30 (1H, m), 2.80 (3H, m), 1.20 (3H, m); m/z (EI⁺, 70V) 549.

EXAMPLE 54 S-3-[4-N-Methyl-(3,5-dichloropyrid-4-ylcarboxamido)-phenyl]-2-(N-methyl-4,6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid

The title compound was prepared from the compound of Example 53 in an analogous manner to Example 2: δH (DMSO d₆) 8.37, (1H, s), 8.32 (1H, s), 7.18 (2H, d, J 8.4 Hz), 7.11 (2H, d, J 8.4 Hz), 5.24 (1H, dd, J 11.0, 5.3 Hz), 3.85 (6H, s), 3.36 (3H, s), 3.19 (2H, m), 2.77 (3H, s); m/z (EI⁺, 70V) 521.

EXAMPLE 55 S-Ethyl [4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-[(6-chloropyridazin-3-yl)amino]propionate

A solution of the compound of Intermediate 3 (420 mg, 1 mmol) in CH₃CN (2 ml) was treated with DIPEA (0.36 ml, 2.1 mmol) and 3,6-dichloropyridazine (164 mg, 1.1 mmol) and heated to reflux temperature for 36 h. The solvent was removed in vacuo, the residue re-dissolved in EtOH (2.5 ml) and a further portion of pyridazine (82 mg, 0.55 mmol) and DIPEA (0.18 ml, 1.1 mmol) were added. The resulting mixture was heated to reflux for 48 h, the solvent was removed in vacuo and the residue was dissolved in EtOAc (20 ml) and washed with 10% citric acid (2×10 ml), NaHCO₃ (2×10 ml) and brine (10 ml), dried (MgSO4) and the solvent removed in vacuo. The product was purified by chromatography (silica 2-5% MeOH/DCM) to give the title compound as a white solid (80 mg, 16%): δH (DMSO d₆) 10.85 (1H, s), 8.77 (2H, s), 7.56 (2H, d, J 8.5 Hz), 7.50 (1H, d, J 7.7 Hz), 7.39 (1H, d, J 9.3 Hz), 7.26 (2H, d, J 8.5 Hz), 7.02 (1H, d, J 9.3 Hz), 4.20 (1H, m), 4.06 (2H, q, J 7.1 Hz), 3.10 (2H, m), 1.12 (3H, t, J 7.1 Hz); m/z (EI⁺, 60V) 494.

EXAMPLE 56 S-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[(6-chloropyridazin-3-yl)amino]propanoic acid

The title compound (50 mg, 79%) was prepared from the compound of Example 55 by hydrolysis in a similar manner to Example 2 (67 mg, 0.14 mmol): δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 7.55 (2H, d, J 8.5 Hz), 7.37 (1H, d, J 9.3 Hz), 7.35 (1H, m), 7.26 (2H, d, J 8.5 Hz), 7.01 (1H, d, J 9.3 Hz), 4.67 (1H, m), 3.17 (1H, dd, J 18.8, 5.0 Hz), 2.96 (1H, dd, J 22.6, 8.9 Hz); m/z (EI⁺, 60V) 466.

EXAMPLE 57 S-Ethyl-3-(4-nitrophenyl)-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

2-Chloro-4,6-dimethoxy-1,3,5-triazine (8.05 g, 45.8 mmol) was added to a solution of (S)-4-nitrophenylalanine ethyl ester hydrochloride (5.0 g, 38.2 mmol) and DIPEA (13.6 ml, 78.3 mmol) in acetonitrile (80 ml) and the reaction was stirred at room temperature for 16 h, concentrated in vacuo and the residue partitioned between EtOAc (100 ml) and NaHCO₃ solution (100 ml). The organic layer was washed with 10% citric acid solution (100 ml), NaHCO₃ solution (100 ml) and water (100 ml), dried (MgSO₄) and concentrated in vacuo. The crude product was purified by chromatography (silica; EtOAc/Hexane 1:1) to give the title compound (6.66 g, 97%): δH (CDCl₃) 8.10 (2H, d, J 9.0 Hz), 7.30 (2H, d, J 9.0 Hz), 6.10 (1H, m), 5.0 (1H, m), 4.1 (2H, q, J 7.1 Hz), 3.92 (3H, s), 3.90 (3H, s), 3.30 (2H, m), 1.25 (3H, t, J 7.1 Hz); m/z (EI⁺, 70V) 378.

EXAMPLE 58 S-Ethyl-3-(4-aminophenyl)-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

Palladium (10% on charcoal) (660 mg) was added to a solution of the compound of Example 57 (6.66 g, 24.3 mmol) in EtOH (100 ml) and stirred under an atmosphere of hydrogen for 16 h. The catalyst was removed by filtration and the solution concentrated in vacuo to give the title compound as a pink solid (5.26 g, 86%) which was used without further purification. δH (CDCl₃) 6.90 (2H, d), 6.60 (2H, d), 5.75 (1H, d), 4.90 (1H, m), 4.10 (2H, q), 3.95 (3H, s), 3.90 (3H, s), 3.10 (2H, m), 1.30 (3H, t); m/z (ES⁺, 70V) 348.

EXAMPLE 59 S-Ethyl-3-[4-(2,6-dichlorophenylcarboxamido)phenyl]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

2,6-Dichlorobenzoyl chloride (0.22 ml, 1.5 mmol) was added to a solution of the compound of Example 58 (0.50 g, 1.4 mmol) and NMM (0.17 ml, 1.5 mmol) in DCM (10 ml). The reaction was stirred at room temperature for 72 h, then partitioned between DCM (50 ml) and NaHCO₃ solution (50 ml). The organic layer was washed with 10% citric acid solution (50 ml), NaHCO₃ solution (50 ml) and water (50 ml), dried (MgSO₄) and concentrated in vacuo to give the title compound as a pink solid (0.61 g, 82%) which was used without further purification: δH (CDCl₃) 7.60 (2H, d), 7.30 (3H, m), 7.10 (2H, d), 5.90 (1H, d), 4.90 (1H, m), 4.20 (2H, m), 3.90 (3H, s), 3.89 (3H, s), 3.20 (2H, m), 1.25 (3H, m); m/z (EI⁺, 70V) 520.

EXAMPLE 60 S-3-[4-(2,6-Dichlorophenylcarboxamido)phenyl]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propanoic acid

The title compound was prepared by hydrolysis in a similar manner to Example 2 from the compound of Example 59: δH (DMSO d₆) 10.70 (1H, s), 8.15 (2H, d), 7.50 (6H, m), 7.25 (2H, d), 4.50 (1H, m), 3.75 (6H, m), 3.00 (2H, m); m/z (EI⁺, 60V) 492.

EXAMPLE 61 S-Ethyl-3-[4-(2-fluoro-6-trifluoromethylphenylcarboxamido)phenyl]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

The title compound was prepared in an analogous manner to the compound of Example 59 using 2-fluoro-6-trifluoromethylbenzoyl chloride: δH (CDCl₃) 7.6 (5H, m), 7.40 (1H, m), 7.10 (2H, d, J 8.0 Hz), 5.90 (1H, d, J 6.0 Hz), 5.0 (1H, m), 4.2 (2H, q), 3.90 (2×3H, s), 3.20 (2H, m), 1.25 (3H, t); m/z (EI⁺, 70V) 538.

EXAMPLE 62 S-3-[4-(2-Fluoro-6-trifluoromethylphenylcarboxamido)phenyl]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propanoic acid

The title compound was prepared from the compound of Example 61 by hydrolysis in a similar manner to Examaple 2: δH (DMSO d₆) 8.10 (2H, m), 7.80 (3H, m), 7.50 (2H, m), 7.30 (2H, m), 4.50 (1H, m), 3.70 (6H, s), 3.00 (2H, m); m/z (EI⁺, 70V) 510.

EXAMPLE 63 S-Ethyl-3-[4-(4,6-dimethoxy-1,3,5-triazin-2-yl)aminophenyl]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

2-Chloro-4,6-dimethoxy-1,3,5-triazine (0.30 g, 1.7 mmol) was added to a solution of the compound of Example 58 (0.50 g, 1.4 mmol) and DIPEA (0.60 ml, 3.2 mmol) in CH₃CN (10 ml). The reaction was stirred at room temperature for 72 h, then concentrated in vacuo, partitioned between EtOAc (50 ml) and NaHCO₃ solution (50 ml). The organic layer was washed with 10% citric acid solution (50 ml), NaHCO₃ solution (50 ml) and water (50 ml), dried (MgSO₄) and concentrated in vacuo to give the title compound as an off white solid (0.23 g, 32%) which was used without further purification: δH (CDCl₃) 7.5 (2H, d, J 9.0 Hz), 7.10 (2H, d, J 9.0 Hz), 6.05 (1H, d, J 6.0 Hz), 5.0 (1H, m), 4.15 (2H, q), 4.05 (6H, s), 3.95 (6H, s), 3.20 (2H, m), 1.25 (3H, m); m/z (EI⁺, 70V) 487.

EXAMPLE 64 S-3-[4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)aminophenyl]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propanoic acid

The title compound was prepared from the compound of Example 63 by hydrolysis in a similar manner to Example 2: δH (DMSO d₆) 10.00 (1H, s), 8.20 (2H, d), 7.55 (2H, d), 7.20 (2H, d), 4.55 (1H, m), 3.90 (6H, s), 3.80 (6H, s), 3.00 (2H, m); m/z (EI⁺, 70V) 459.

EXAMPLE 65 S-Ethyl 3-[4-(4,6-dimethoxy-1,3,5-triazin-2-yl)phenoxy]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

A solution of Intermediate 11 (0.50 g, 1.43 mmol) in DMF (10ml) was treated with caesium carbonate (0.94 g, 2.86 mmol) and stirred at room temperature for 15 min. 2-Chloro-4,6-dimethoxy-1,3,5-triazine (0.25 g, 1.43 mmol) was added and the reaction stirred for 16 h then concentrated in vacuo, and partitioned between EtOAc (50 ml) and water (50 ml). The organic layer was separated, dried (MgSO4) and concentrated in vacuo to give the title compound as an off-white solid (0.47 g, 67%): δH (DMSO d₆) 7.25 (2H, d, J 7.0 Hz), 7.20 (2H, d, J 7.0 Hz), 5.90 (1H, d), 5.00 (1H, m), 4.20 (2H, m), 4.00 (12H, s), 3.20 (2H, m), 1.20 (3H, t, J 7.1 Hz); m/z (EI⁺, 70V) 488.

EXAMPLE 66 S-3-[4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)phenoxy]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propanoic acid

The title compound was prepared from the compound of Example 65, by hydrolysis in a similar manner to Example 2: δH (DMSO d₆) 8.00 (1H, s), 7.35 (2H, d, J 8.0 Hz), 7.10 (2H, d, J 8.0 Hz), 4.50 (1H, m), 3.85 (6H, s), 3.79 (6H, s), 3.77 (6H, s), 3.20 (2H, m); m/z (EI⁺, 70V) 460.

EXAMPLE 67 S-Ethyl 3-[4-(2,6-dichlorobenzyl)phenoxy]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propionate

A solution of Intermediate 11 (0.50 g, 1.43 mmol) in DMF (10 ml) was treated with caesium carbonate (0.94 g, 2.86 mmol) and stirred at room temperature for 15 min. 2,6-Dichlorobenzyl bromide (0.38 g, 1.58 mmol) was added and the reaction stirred for 16 h then concentrated in vacuo, and partitioned between EtOAc (50 ml) and water (50 ml). The organic layer was separated, washed with water (2×50 ml), dried (MgSO4) and concentrated in vacuo. The residue was purified by chromatography (silica; EtOAc/Hexane 1:1) to give the title compound as an oil (0.26 g, 36%): δH (DMSO d₆) 7.45 (1H, m), 7.40 (1H, m), 7.35 (1H, m), 7.10 (2H, d), 6.90 (2H, d), 5.8 (1H, d), 5.25 (2H, s), 4.10 (2H, m), 3.90 (6H, s), 3.10 (2H, m), 1.3 (3H, m); m/z (EI⁺, 70V) 507.

EXAMPLE 68 S-3-[4-(2,6-Dichlorobenzyl)phenoxy]-2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]propanoic acid

The title compound was prepared from the compound of Example 67, by hydrolysis in a similar manner to Example 2: δH (DMSO d₆) 8.10 (1H, d), 7.50 (2H, m), 7.45 (1H, m), 7.25 (2H, d, J 8.0 Hz), 6.95 (2H, d, J 8.0 Hz), 5.15 (2H, m), 4.50 (1H, m), 3.80 (3H, s), 3.75 (3H, s), 3.00 (2H, m); m/z (EI⁺, 70V) 479.

EXAMPLE 69 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-(propylsulphonyl)pyrazin-2-ylamino]propanoic acid

The title compound was prepared in an analogous manner to the compound of Example 1 starting from Intermediate 3 and Intermediate 12, followed by hydrolysis: δH (DMSO d₆) 10.86 (1H, s), 8.77 (2H, s), 8.40 (1H, d, J 2.3 Hz), 7.99 (1H, d, J 2.3 Hz), 7.55 (2H, d, J 8.5 Hz), 7.37 (1H, d, J 7.0 Hz), 7.18 (2H, d, J 8.5 Hz), 4.80 (1H, br. q), 3.38-3.22 (3H, m), 3.10 (1H, dd, J 13.9, 7.0 Hz), 1.55-1.46 (2H, m), 0.88 (3H, t, J 7.4 Hz); m/z (EI⁺, 70V) 538.

EXAMPLE 70 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-chloropyrazin-2-ylamino]propanoic acid

The title compound was prepared in an analogous manner to the compound of Example 5 starting from Intermediate 3 and 2,3-dichloropyrazine, followed by hydrolysis: δH (DMSO d₆) 12.81 (1H, br. s), 10.83 (1H, s), 8.77 (2H, s), 7.99 (1H, d, J 2.7 Hz), 7.61 (1H, d, J 2.7 Hz), 7.54 (2H, d, J 8.5 Hz), 7.28 (2H, d, J 8.5 Hz), 6.87 (1H, d, J 7.9 Hz), 4,68-4.61 (1H, m), 3.22 (2H, m); m/z (EI⁺, 70V) 466.

EXAMPLE 71 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[6-chloropyrazin-2-ylamino]propanoic acid

The title compound was prepared in an analogous manner to the compound of Example 5 starting from Intermediate 3 and 2,6-dichloropyrazine, followed by hydrolysis: δH (DMSO d₆) 12.82 (1H, br. s), 10.84 (1H, s), 8.77 (2H, s), 7.97 (1H, s), 7.84 (1H, d, J 8.0 Hz), 7.72 (1H, s), 7.54 (2H, d, J 8.5 Hz), 7.27 (2H, d, J 8.5 Hz), 4.51 (1H, ddd, J 8.9, 8.0, 4.9 Hz), 3.15 (1H, dd, J 13.9, 4.4 Hz), 2.96 (1H, dd, J 13.9, 9.1 Hz); m/z (EI⁺, 70V) 466.

EXAMPLE 72 S-Ethyl 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-chloroquinoxalin-2-ylamino]propionate

The title compound was prepared in an analogous manner to the compound of Example 5 starting from Intermediate 3 and 2,3-dichloroquinoxaline. The product contains some ethoxyethylester as a result of transesterification in the ethoxyethanol used as solvent in this case: δH (DMSO d₆) 10.38 (1H, s), 8.76 (2H, s), 7.76 (1H, d, J 8.2 Hz), 7.65-7.41 (6H, m), 7.32 (2H, d, J 8.4 Hz), 4.82-4.75 (1H, m), 4.17-4.06 (2H, m), 3.40-3.20 (2H, m), 1.14 (3H, t, J 7.1 Hz); m/z (ES⁺, 70V) 544. For the ethoxyethyl ester: δH (DMSO d₆) 3.47-3.42 (m). 0.97 (3H, t, J 7.0 Hz); m/z (EI⁺, 70V) 588.

EXAMPLE 73 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-chloroquinoxalin-2-ylamino]propanoic acid

The title compound was prepared from the compound of Example 72 by hydrolysis: δH (DMSO d₆) 12.84 (1H, br. s), 10.81 (1H, s), 8.76 (2H, s), 7.76 (1H, d, J 8.2 Hz), 7.63-7.61 (2H, m), 7.54 (1H, d, J 8.5 Hz), 7.46-41 (1H, m), 7.33-7.25 (3H, m), 4.86-4.79 (1H, m), 3.30-3.26 (2H, m); m/z (EI⁺, 70V) 516.

EXAMPLE 74 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-phenoxyquinoxalin-2-ylamino]propanoic acid

The title compound was prepared in an analogous manner to the compound of Example 5 starting from Intermediate 3 and Intermediate 14 followed by hydrolysis: δH (DMSO d₆) 12.90 (1H, br. s), 10.83 (1H, s), 8.76 (2H, s), 7.57-7.23 (14H, m), 4.91-4.84 (1H, m), 3.30 (2H, br. d J 6.6 Hz); m/z (EI⁺, 70V) 574.

EXAMPLE 75 S-Ethyl 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-morpolinoquinoxalin-2-ylamino]propionate

A mixture of the compound of Example 73 (300 mg, 0.55 mmol), morpholine (58 μl, 0.66 mmol) and DIPEA (192 μL, 1.1 mmol) in ethoxyethanol (2 ml) was heated at reflux overnight. The solvent was removed in vacuo. The residue was dissolved in DCM, washed with dil. HCl, dried (Na₂SO₄) and evaporated in vacuo. Column chromatography (silica; EtOAc/Hexane 6:4) gave the title compound (280 mg) as a brown oil, which contains some of the corresponding ethoxyethyl ester from transesterification: δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 7.61-7.27 (8H, m), 6.70 (1H, d, J 7.8 Hz), 4.75 (1H, m), 4.21-4.07 (2H, m and ethoxyethyl ester), 3.86-3.80 (2H, m), 3.71-3.66 (2H, m), 3,50 (m, ethoxyethyl ester), 3.30 (2H, m), 3.12-3.17 (2H, m), 2.97-2.91 (2H, m), 1.16 (t, J 7.1 Hz) and 1.00 (t, J 7.0 Hz) together (3H); m/z (EI⁺, 70V) 595, 639 (ethoxyethyl ester).

EXAMPLE 76 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[3-morpolinoquinoxalin-2-ylamino]propanoic acid

The title compound was prepared by starting from the compound of Example 75 followed by hydrolysis: δH (DMSO d₆) 10.83 (1H, s), 8.76 (2H, s), 7.61-7.26 (8H, m), 6.55 (1H, d, J 7.8 Hz), 4.74 (1H, m), 3.84-3.79 (2H, m), 3.69-3.64 (2H, m), 3.30-3.20 (2H, m), 3.20-3.10 (2H, m), 2.93-2.88 (2H, m); m/z (EI⁺, 70V) 567.

EXAMPLE 77 Ethyl 2-[4-(3,5-dichloropyrid-4-ylcarboxamido)benzyl]-3-[6-(propylsulphonyl)-pyrimidin-4-ylamino]propionate

A mixture of Intermediate 19 (440 mg, 1.11 mmol) Intermediate 13 (271 mg, 0.93 mmol) and DIPEA (193 μl, 1.11 mmol) in CH₃CN (5 ml) was stirred at room temperature for 2 h. The solvent was removed in vacuo and the residue dissolved in DCM, washed with dil. HCl, dried (Na₂SO₄) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM 5:95) gave the title compound as a colourless oil (400 mg): δH (DMSO d₆) 10.85 (1H, s), 8.78 (2H, s), 8.30 (1H, br. t, J 5.7 Hz), 7.55 (2H, d, J 8.5 Hz), 7.20 (2H, d, J 8.5 Hz), 7.10 (1H, s), 3.97 (2H, q, J 7.4 Hz), 3.60 (2H, br. m), 3.36-3.27 (4H, m), 2.99, (1H, m), 1.58 (2H, sext, J 7.5 Hz), 1.03 (3H, t, J 7.1 Hz), 0.93 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 580.

EXAMPLE 78 2-[4-(3,5-Dichloropyrid-4-ylcarboxamido)benzyl]-3-[6-(propylsulphonyl)-pyrimidin-4-ylamino]propanoic acid

The title compound was prepared by hydrolysis from the compound of Example 77 in a similar manner to Example 2.: δH (DMSO d₆) 12.38 (1H, br. s), 10.85 (1H, s), 8.78 (2H, s), 8.57 (1H, s), 8.30 (1H, br, m), 7.55 (2H, d, J 8.5 Hz), 7.21 (2H, d, J 8.5 Hz), 7.12 (1H, s), 3,55 (2H, br. m), 3.33-3.29 (4H, m), 2.95-2.83, (1H, m), 1.59 (2H, sext, J 7.6 Hz), 0.94 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 552.

EXAMPLE 79 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-benzyloxybenzeneamino)propionate

A solution of Intermediate 20 (500 mg, 1.3 mmol), 3-benzyloxyaniline (1.1 equiv) and rhodium (II) acetate dimer (5 mol%) in anhydrous toluene (20 ml) were stirred at 80° for 7 h. The mixture was cooled and the volatiles removed in vacuo. The residue was purified by chromatography (silica; 1% MeOH/DCM) to give the title compound (500 mg, 70%): δH (CDCl₃) 8.50 (2H, s), 8.06 (1H, br. s), 7.49 (2H, d, J 8.5 Hz), 7.43-7.26 (6H, m), 7.14 (2H, d, J 8.5 Hz), 7.05 (1H, t, J 8.5 Hz), 6.37 (1H, d, J 7.3 Hz), 6.24 (2H, m), 5.00 (2H, s), 4.40-4.08 (4H, m), 3.13 (1H, dd, J 13.4, 7 Hz), 3.02 (1H, dd, J 13.4, 5.9 Hz), 1.20 (3H, t, J 7.2 Hz): m/z (EI⁺, 70V) 564.

EXAMPLE 80 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylthiobenzeneamino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from 3-propylthioaniline: δH (CDCl₃) 8.56 (2H, s), 7.72-7.58 (2H, m), 7.53 (2H, d, J 8.5Hz), 7.10 (2H, d, J 8.4 Hz), 7.04 (1H, t, J 7.9 Hz), 6.68 (1H, d, J 7.9 Hz), 6.57 (1H, s), 6.42 (1H, d), 4.40-4.10 (3H, m), 3.25-3.07 (2H, m), 2.83 (2H, t, J 7.3 Hz), 1.63 (2H, m), 1.21 (3H, t, J 6.8 Hz), 1.01 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 532.

EXAMPLE 81 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-ethoxycarbonylbenzeneamino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from ethyl 4-aminobenzene carboxylate: δH (CDCl₃) 8.58 (2H, s), 7.85 (2H, d, J 8.8Hz), 7.56-7.51 (3H, m), 7.15 (2H, d, J 8.5 Hz), 6.56 (1H, d, J 8.8 Hz), 4.70-4.60 (1H, br. m), 4.55-4.45 (1H, br. m), 4.32 (2H, q, J 7.2Hz), 4.16 (2H, q, J 7.1 Hz), 3.30-3.14 (2H, m), 1.33 (3H, t, J 7.2 Hz), 1.23 (3H, t, J 7.1 Hz): m/z (EI⁺, 70V) 530.

EXAMPLE 82 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylbenzeneamino)propionate

The title compound was prepared by oxidation of the compound of Example 80 with mCPBA: δH (CDCl₃) 8.47 (2H, s), 8.36 (1H, br. s), 7.51 (2H, d, J 8.5 Hz), 7.30 (1H, t, J 7.9 Hz), 7.12 (2H, d, J 8.4 Hz), 7.01 (1H, m), 6.78 (1H, m), 4,61 (1H, br. m), 4.40 (1H, br. m), 4.10 (2H, q, J 5.9 Hz), 3.15 (1H, dd, J 13.9, 5.6 HZ), 3.05 (1H, dd, J 13.9, 6.3 Hz), 2.95 (2H, m), 1.61 (2H, m), (3H, t, J 7.2 Hz), 0.94 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 564.

EXAMPLE 83 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphinylbenzeneamino)propionate

The title compound was prepared by oxidation of the compound of Example 80 with mCPBA: δH (CDCl₃) 9.11 (1H, d, J 8.3 Hz), 8.44 (2H, s), 7.56 (2H, d, J 8.0 Hz), 7.21 (1H, t, J 7.8 Hz), 7.12 (2H, m), 6.80-6.64 (3H, m), 4.65-4.35 (2H, br. m), 4.10 (2H, q, J 7.1 Hz), 3.20-3.00 (2H, m), 2.70-2.50 (2H, m), 1.80-1.50 (2H, m), (3H, t, J 8.7 Hz), 0.99 (3H, t, J 7.5 Hz): m/z (EI⁺, 70V) 548.

EXAMPLE 84 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-ethylacetatobenzeneamino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from ethyl 4-aminobenzene acetate: δH (CDCl₃) 8.57 (2H, s), 7.81 (2H, d, J 8.5 Hz), 7.17 (2H, d, J 8.5 Hz), 7.06 (2H, d, J 8.8 Hz), 6.55 (2H, d, J 8.6 Hz), 4.30 (1H, br. m), 4.10 (4H, m), 3.48 (2H, s), 3.25-3.00 (2H, m), 1.20 (6H, m): m/z (EI⁺, 70V) 544.

EXAMPLE 85 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-acetylbenzeneamino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from 3-amino acetophenone: δH (CDCl₃) 8.56 (2H, s), 7.65 (1H, br. m), 7.40-7.10 (5H, m), 6.80 (1H, m), 4.50-4.30 (2H, br. m), 4.16 (2H, q, J 7.2 Hz), 3.25-3.10 (2H, m), 2.54 (3H, s), 1.22 (3H, t, J 7.2 Hz): m/z (EI⁺, 70V).

EXAMPLE 86 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-chloro-pyridine-3-amino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from 3-amino-2-chloro-pyridine: δH (CDCl₃) 8.56 (2H, s), 7.78 (1H, br. s), 7.70 (1H, d, J 4.7 Hz), 7.56 (2H, d, J 8.5 Hz), 7.20 (2H, d, J 8.5 Hz), 7.04 (1H, m), 6.78 (1H, m, J 8.0, 1.3 Hz), 4.87 (1H, br. m), 4.40-4.15 (3H, m), 3.18 (1H, dd, J 14.0, 5.7 Hz), 3.11 (1H, dd, J 13.7, 6.6 Hz), 1.23 (3H, t, J 7.1 Hz): m/z (EI⁺, 70V) 493.

EXAMPLE 87 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-benzoylbenzeneamino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from 3-amino benzophenone: δH (CDCl₃) 8.55 (2H, s), 7.72 (2H, d, J 8.5 Hz), 7.70-7.40 (6H, m), 7.30-7.00 (6H, m), 6.80 (1H, m), 4.40 (1H, br. m), 4.15 (2H, q, J 7.2 Hz), 3.40-3.20 (2H, m,), 1.20 (3H, t, J 7.2 Hz): m/z (EI⁺, 70V) 562.

EXAMPLE 88 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-ethoxycarbonylbenzeneamino) propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from ethyl 3-aminobenzoate: δH (CDCl₃) 8.44 (2H, s), 7.50 (2H, d, J 8.4 Hz), 7.35 (1H, d, J 7.7 Hz), 7.30-7.10 (4H, m), 6.77 (1H, m), 4.40 (1H, br. s), 4.31 (2H, q, J 7.2 Hz), 4.09 (2H, m), 3.25-3.00 (2H, m), 1.33 (3H, t, J 7.2 Hz), 1.21 (3H, t, J 7.2 Hz): m/z (EI⁺, 70V) 530.

EXAMPLE 89 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylthiopyridine-2-amino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from Intermediate 23: δH (CDCl₃) 8.53 (2H, s), 8.11 (1H, s), 7.87 (1H, s), 7.54 (2H, d, J 8.4 Hz), 7.19 (2H, d, J 8.4 Hz), 6.17 (1H, s), 4.80 (1H, br. m), 4.21 (2H, q, J 7.1 Hz), 3.21 (1H, dd, J 14.0, 5.5 Hz), 3.09 (1H, dd, J 14.0, 5.7 Hz), 2.80 (2H, t, J 7.2 Hz), 1.74 (2H, m), 1.30 (3H, t, J 7.1 Hz), 1.07 (3H, t, J 7.3 Hz): m/z (EI⁺, 70V 568.

EXAMPLE 90 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphinylpyridine-2-amino)propionate

The title compound was prepared by oxidation of the compound of Example 89 with mCPBA: δH (CDCl₃) 8.55 (2H, s), 7.94 (2H, m), 7.52 (2H, d, J 8.4 Hz), 7.12 (2H, m), 6.82 (1H, d), 4.90 (1H, m), 4.20 (2H, m), 3.40-3.00 (3H, m), 2.90-2.70 (1H, m), 2.00-1.60 (2H, m), 1.25 (3H, t, J 7.2 Hz), 1.07 (3H, t, J 7.2 Hz): m/z (EI⁺, 70V) 584.

EXAMPLE 91 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphonylpyridine-2-amino)propionate

The title compound was prepared by oxidation of the compound of Example 89 with m-chloroperoxybenzoic acid: δH (CDCl₃) 8.56 (2H, s), 8.19 (1H, s), 7.63 (1H, br. s), 7.51 (2H, d, J 8.4 Hz), 7.17 (2H, d, J 8.4 Hz), 7.14 (1H, s), 5.34 (1H, br. m), 4.21 (2H, q, J 7.2 Hz), 3.30 (2H, t, J 7.9 Hz), 3.35-3.10 (2H, m), 1.70 (2H, m), 1.29 (3H, t, J 7.2 Hz), 1.01 (3H, t, J 7.5 Hz): m/z (EI⁺, 70V) 598.

EXAMPLE 92 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloropyridine-2-amino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from 2-amino-5-chloro-pyridine: δH (CDCl₃) 8.56 (2H, s), 8.03 (1H, m), 7.59 (1H, m), 7.15 (2H, d, J 8.5 Hz), 6.37 (1H, d, J 8.9 Hz), 4.84 (1H, br. m), 4.15 (2H, q, J 7.2Hz), 3.30-3.10 (2H, m), 1.20 (3H, t, J 7.2 Hz).

EXAMPLE 93 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-propylthiopyridine-2-amino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from 2-amino-4-propylthio-pyridine: δH (CDCl₃) 8.51 (2H, s), 8.40 (1H, br. s), 7.81 (1H, d, J 5.6 Hz), 7.49 (2H, d, J 8.5 Hz), 7.13 (2H, d, J 8.5 Hz), 6.44 (1H, dd, J 5.6, 1.6 Hz), 6.19 (1H, d, J 1.2 Hz), 4.95-4.72 (2H, m), 4.15 (2H, q, J 7.1 Hz), 3.30-3.05 (2H, m), 2.80 (2H, t, J 7.4 Hz), 1.70 (2H, m), 1.22 (3H, t, J 7.1 Hz), 1.01 (3H, t, J 7.4 Hz).

EXAMPLE 94 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-propylsulphonylpyridine-2-amino)propionate

The title compound was prepared by oxone oxidation of the compound of Example 93: δH (CDCl₃) 8.56 (2H, s), 8.23 (1H, d, J 5.3 Hz), 7.68 (1H, br. m), 7.53 (2H, d, J 8.5 Hz), 7.20 (2H, d, J 8.5 Hz), 6.96 (1H, m), 6.90 (1H, s), 4.90 (1H, br. m), 4.19 (2H, q, J 7.1 Hz), 3.40-3.10 (2H, m), 3.01 (2H, m), 1.70 (2H, m), 1.25 (3H, t, J 7.2 Hz), 1.02 (3H, t, J 7.5 Hz): m/z (EI⁺, 70V) 565.

EXAMPLE 95 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-methoxycarbonyl-4-propylthiopyridine-2-amino)propionate

The title compound was prepared by a similar procedure to the compound of Example 79, starting from ethyl 2-amino-4-propylthio-pyridine-5carboxylate: δH (CDCl₃) 8.65 (1H, s), 8.53 (2H, s), 8.05 (1H, br. s), 7.52 (2H, d, J 8.5 Hz), 7.20 (2H, d, J 8.5 Hz), 6.20 (1H, s), 5.62 (1H, br. m), 4.92 (1H, br. m), 4.20 (2H, q, J 7.2 Hz), 3.90 (3H, s), 3.40-3.10 (2H, m), 2.72 (2H, t, J 7.4 Hz), 1.72 (2H, m), 1.22 (3H, t, J 7.2 Hz), 1.10 (3H, t, J 7.4 Hz).

EXAMPLE 96 Ethyl 3-[4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(5methoxycarbonyl-4-propylsulphonylpyridine-2-amino)propionate

The title compound was prepared by oxone oxidation of the compound of Example 95: isolated crude and used without further purification in Example 112.

EXAMPLE 97 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-benzyloxybenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 79: δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 7.53 (2H, d, J 8.6 Hz), 7.42-7.26 (7H, m), 6.92 (1H, t, J 8.0 Hz), 6.17 (3H, m), 4.97 (2H, s), 4.05 (1H, br. m), 3.29-2.89 (2H, m): m/z (EI⁺, 70V) 536.

EXAMPLE 98 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylthiobenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 80: δH (DMSO d₆) 10.83 (1H, s), 8.77 (2H, s), 7.53 (2H, d, J 8.5 Hz), 7.27 (2H, d, J 8.5 Hz), 6.95 (1H, t, J 7.9 Hz), 6.52-6.30 (3H, m), 4.10 (1H, br. m), 3.20-2.90 (2H, m), 2.80 (2H, t, J 7.2 Hz), 1.52 (2H, m), 0.92 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 504.

EXAMPLE 99 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-carboxybenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 81: δH (DMSO d₆) 10.83 (1H, s), 8.77 (2H, s), 7.65 (2H, d, J 8.7 Hz), 7.53 (2H, d, 8.5 Hz), 7.27 (2H, d, J 8.5 Hz), 6.76 (1H, d, J 8.6 Hz), 6.60 (2H, d, J 8.7 Hz), 4.22 (1H, br. m), 3.30-2.95 (2H, m): m/z (EI⁺, 70V) 574.

EXAMPLE 100 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylbenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 82: δH (DMSO d₆) 10.84 (1H, s), 8.77 (1H, s), 7.53 (2H, d, J 8.5 Hz), 7.29 (3H, m), 7.28 (1H, s), 7.01 (1H d, J 7.6 Hz), 6.86 (1H, d, J 8.1 Hz), 6.55(1H, d, J 8.9 Hz), 4.20(1H, br. m), 3.17-3.11 (3H, m), 2.91 (1H, dd, J 13.8, 8.7 Hz), 1.48 (2H, m), 0.86 (3H, t, J 7.5 Hz): m/z (EI⁺, 70V) 536.

EXAMPLE 101 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphinylbenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 83: δH (DMSO d₆) 12.75 (1H, br. s), 10.89 (1H, s), 8.80 (2H, s), 7.55 (2H, d, J 8.5 Hz), 7.31 (2H, d, J 8.5 Hz), 7.21 (1H, t, J 7.9 Hz), 6.84 (1H, s), 6.76-6.68 (2H, m), 6.42 (1H, br. m), 3.33 (2H, t, J 8.9 Hz), 3.30-2.50 (4H, m), 1.80-1.30 (2H, m), 0.93 (3H, t, J 7.2 Hz): m/z (EI⁺, 70V) 520.

EXAMPLE 102 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-carboxymethylbenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 84: δH (DMSO d₆) 10.83 (1H, s), 8.76 (2H, s), 7.53 (2H, d, J 8.5 Hz), 7.27 (2H, d, J 8.5 Hz), 6.92 (2H, d, J 8.5 Hz), 6.51 (2H, d, J 8.5 Hz), 4.00 (1H, br. m), 2.95 (2H, m): m/z (EI⁺, 70V) 488.

EXAMPLE 103 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-acetylbenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 85: δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 7.53 (2H, d, J 8.5 Hz), 7.29 (2H, d, J 8.5 Hz), 7.30-7.10 (3H, m), 6.82 (1H, m), 6.20 (1 H, br. m), 4.17 (1H, br. m), 3.20-2.90 (2H, m): m/z (EI⁺, 70V) 472.

EXAMPLE 104 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-chloro-pyridine-3-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 86: δH (DMSO d₆) 10.85 (1H, s), 8.77 (2H, s), 7.75-7.50 (3H, m), 7.40-7.10 (4H, m), 5.28 (1H, d, J 8.4 Hz), 4.40 (1H, br. m), 3.15 (2H, d, J 5.9 Hz): m/z (EI⁺, 70V) 467.

EXAMPLE 105 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-benzoylbenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 87: δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 7.90-7.40 (6H, m), 7.35-7.10 (3H, m), 7.05-6.80 (3H, m), 6.30 (1H, m), 4.14 (1H, br. m), 3.20-2.80 (2H, m): m/z (EI⁺, 70V) 534.

EXAMPLE 106 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-carboxybenzeneamino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 88: δH (DMSO d₆) 12.61 (1H, br. s), 10.84 (1H, s), 8.77 (2H, s), 7.54 (2H, d, J 8.5 Hz), 7.30 (2H, d, J 8.5 Hz), 7.13 (3H, m), 6.78 (1H, m), 6.20 (1H, br. m), 4.12 (1H, br. m), 3.20-2.90 (2H, m): m/z (EI⁺, 70V) 474.

EXAMPLE 107 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylthiopyridine-2-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 89: δH (DMSO d₆) 10.83 (1H, s), 8,.77 (2H, s), 7.81 (1H, s), 7.53 (2H, d, J 8.4 Hz), 7.23 (2H, d, J 8.4 Hz), 6.54 (1H, s), 4.56 (1H, m), 3.20-2.80 (4H, m), 1.63 (2H, m), 0.99 (3H, t, J 7.3 Hz): m/z (EI⁺, 70V) 540.

EXAMPLE 108 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphinylpyridine-2-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 90: δH (DMSO d₆) 12.48 (1H, br. s), 10.72 (1H, s), 8.65 (1H, s), 7.86 (1H, s), 7.70-7.40 (3H, m), 7.20 (2H, m), 6.88 (1H, m), 4.40 (1H, br. m), 3.10-2.90 (2H, m), 2.90-2.50 (2H, m), 1.80-1.30 (2H, m), 0.85 (3H, m): m/z (EI⁺, 70V) 555.

EXAMPLE 109 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphonylpyridine-2-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 91: δH (DMSO d₆) 10.84 (1H, s), 8.77 (2H, s), 8.18 (1H, s), 7.80 (1H, br. m), 7.53 (2H, d, J 8.5 Hz), 7.26 (3H, m), 4.60 (1H, m), 3.41 (2H, m), 3.30-3.10 (1H, m), 3.10-2.80 (1H, m), 1.50 (2H, m), 0.91 (3H, t, J 7.5 Hz): m/z (EI⁺, 70V) 571.

EXAMPLE 110 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloropyridine-2-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 92: δH (DMSO d₆) 12.40 (1H, br. s), 10.71 (1H, s), 8.68 (2H, s), 7.79 (1H, s), 7.40 (2H, d, J 8.4 Hz), 7.28 (1H, m), 7.12 (2H, d, J 8.4 Hz), 6.91 (1H, d, J 8.2 Hz), 6.47 (1H, d, J 8.9 Hz), 4.45 (1H, m), 2.95 (1H, m), 2.77 (1H, m): m/z (EI⁺, 70V) 465.

EXAMPLE 111 3-[4-3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-propylsulphonylpyridine-2-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 94: δH (DMSO d₆) 10.86 (1H, s), 8.78 (2H, s), 8.19 (1H, d, J 5.3 Hz), 7.55 (3H, m) 7.28 (2H, d, J 8.5 Hz), 7.07 (1 H, s), 6.88 (1H, m), 4.64 (1H, br. m), 3.27 (2H, t, J 7.7 Hz), 3.12 (1H, m), 2.92 (1H, m), 1.50 (2H, m), 0.91 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 537.

EXAMPLE 112 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-propylsulphonylpyridine-2-amino)propanoic acid

The title compound was prepared by lithium hydroxide hydrolysis of the compound of Example 96: δH (DMSO d₆) 13.0 (1H, br. s), 10.85 (1H, s), 8.78 (2H, s), 8.48 (1H, s), 7.55 (2H, d, J 8.6 Hz), 7.26 (3H, m), 4.70 (1H, br. m), 3.66 (2H, t, J 7.7 Hz), 3.40-2.90 (2H, m), 1.58 (2H, m), 0.94 (3H, t, J 7.4 Hz): m/z (EI⁺, 70V) 581.

EXAMPLE 113 S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-trifluormethylpyrimidin-2-ylamino)propanoic acid

The title compound was prepared from Intermediate 3 and methyl 2-chloro-4-(trifluoromethyl)pyrimidine 5-carboxylate, followed by hydrolysis: δH (DMSO d₆) 10.80 (1H, br s), 8.77 (1H, s), 8.75 (2H, s), 8.51 and 8.38 (together 1H, d, J 8.0 Hz), 7.53 (2H, d, J 8.0 Hz), 7.32 (2H, d, J 8.0 Hz), 4.65-4.50 (1H, br m), 3.21 (1H, dd, J 13.9, 3.9 Hz) and 3.03 (1H, dd, J 13.9, 10.4 Hz); m/z (EI⁺, 60V) 545.

EXAMPLE 114 S-ethyl-3-[4-(3,5-dichloro-1-oxido-4-pyridiniocarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-yl)propanoate and S-ethyl-3-[4-(3,5-dichloro-1-oxido-4-pyridiniocarboxamidophenyl]-2-(6-propylsulphonyl-1-oxido-4-pyrimidinio)propanoate

A solution of the compound of Example 6 (14.0 g, 25.2 mmol) and mCPBA (30 g, 105 mmol assuming 60% pure) in dichloromethane (300 ml) were stirred at room temperature for 8 h. The mixture was then treatd with 10% aqueous sodium sultite solution (200 ml) and stirred for 5 mins. A further 200 ml of DCM was added before washing consecutively with saturated aqueous NaHCO₃ (200 ml), brine (200 ml) and water (200 ml) dried (MgSO₄) and evaporated in vacuo. The yellow solid obtained was chromatographed (silica; ethyl acetate→ethyl acetate/methanol (10%)) to afford S-ethyl-3-[4-(3,5-dichloro-1-oxido-4-pyridiniocarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-yl)propanoate (3.0 g) and S-ethyl-3-[4-(3,5-dichloro-1-oxido-4-pyridinioarboxamidophenyl]-2-(6-propylsulphonyl-1-oxido-4-pyrimidinio)propanoate (5.5 g). These materials were used without further characterisation in Examples 115 and 116.

EXAMPLE 115 S-3-[4-(3,5-Dichloro-1-oxido-4-pyridiniocarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylamino)propanoic acid

A solution of the mono-N-oxide from Example 114 (3.0 g, 5.2 mmol) and lithium hydroxide monohydrate (0.32 g, 7.74 mmol) in THF/H₂O (1:1, 100 ml) was stirred overnight at room temperature. THF was removed by evaporation in vacuo, and water (100 ml) added. The reaction mixture as made pH3 with hydrochloric acid (1M) and then filtered and precipiate collected and dried. Purification by recrystalisation (acetonitrile/H₂O) gave the title compound as a white powder (500 mg, 17%). δH (DMSO d₆) 10.83 (1H, s), 8.72 (2H, s), 8.57 (1H, s), 8.45 (1H, d, J 7.7 Hz), 7.55 (2H, d, J 8.5 Hz), 7.27 (2H, d, J 8.5 Hz), 7.22 (1H, s), 4.78 (1H, dt, J 8.6, 5.0 Hz), 3.2 (m, obscured by H₂O), 3.00 (2H, dd, J 13.9, 9.11 Hz), 1.59 (2H, q, J 7.6 Hz), 0.94 (3H, t, J 7.4 Hz); m/z (EI⁺, 80V) 554.

EXAMPLE 116 S-3-[4-(3,5-Dichloro-1-oxido-4-pyridiniocarboxamido)phenyl]2-(6-propylsulphonyl-1-oxido-4-pyrimidinioamino)propanoic acid

A solution of the di-N-oxide from Example 114 (5.5 g, 9.2 mmol) and lithium hydroxide monohydrate (0.6 g, 13.8 mmol) in THF/H₂O 1:1 (100 ml) was stirred overnight at room temperature. The THF was then removed in vacuo and the remaining solution diluted with H₂O (100 ml), before 1M HCl added to make the pH3. The precipitate was collected by filtration, dried to give the title compound as a pale yellow solid (40 g, 76%). δH (DMSO d₆) 10.83 (1H, s), 8.72 (2H, s), 8.57 (1H, s), 8.45 (1H, d, J 7.7 Hz), 7.55 (2H, d J 8.5 Hz), 7.27 (2H, d, J 8.5 Hz), 7.22 (1H, s), 4.78 (1H, m), 3.2 (m, obscured by H₂O), 1.60 (2H, q, J 7.6 Hz), 0.93 (3H, t, J 7.4 Hz); m/z (EI⁺, 80V) 572.

EXAMPLE 117 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylpyrid-2-ylamino)propanoic acid

A mixture of Intermediate 25 (150 mg), dirhodiumtetraacetate, (1.8 mg, 5.1 μmols) and 2-amino-6-propylpyridine in anhydrous toluene (2.5 mL) was agitated at ambient temperature for 0.5 h then at 80° C. for 6 h. The resin was filtered and then washed with DCM, DMF, methanol, water, methanol, DMF and DCM. The resin was treated with 50% trifluoroacetic acid in DCM (4.0 ml) for 3 h with agitation and filtered. The resin was then washed with a 4.0 ml portion of DCM. The combined filtrate was evaporated in vacuo to give the crude product (48 mg) which was purified by preparative HPLC to afford the title compound (2.7 mg). HPLC-MS Retention time 2.19 min; MH⁺473.

HPLC-MS

HPLC-MS was performed on a Hewlett Packard 1100/MSD ES Single Quadropole system with diode array detector using a Luna C18(2) 50×2.0 mm (3 μm) column, running a gradient of 95% [0.1% aqueous formic acid], 5% [0.1% formic acid in acetonitrile] to 10% [0.1% aqueous formic acid], 90% [0.1% formic acid in acetonitrile] over 2 min, then maintaining the mobile phase at that ratio for a further 1 min. Flow rate 0.8 ml/min. MS was acquired by API electrospray in positive ion mode, at 70V, scanning from 150 to 750 amu.

The following compounds of Examples 118-168 were prepared in a similar manner to the compound of Example 117, each using the starting material shown in place of 2-amino-6-propylpyridine.

EXAMPLE 118 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-methylisoxazol-5-ylamino)propanoic acid

5-Amino-3-methylisoxazole gave the title compound (0.7 mg) HPLC-MS Retention time 2.37 min; MH⁺ 435.

EXAMPLE 119 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[2-acetyl-5-(4-chlorophenyl)thien-3-ylamino]propanoic acid

2-Acetyl-3-amino-5-(4-chlorophenyl)thiophene gave the title compound (2.6 mg)

HPLC-MS Retention time 2.90 min; MH⁺ 588.

EXAMPLE 120 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-methylquinol-6-ylamino)propanoic acid

6-Amino-2-methylquinoline gave the title compound (5.0 mg)

HPLC-MS Retention time 2.17 min; MH⁺ 495.

EXAMPLE 121 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(quinol-6-ylamino)propanoic acid

6-Aminoquinoline gave the title compound (3.3 mg)

HPLC-MS Retention time 2.15 min; MH⁺ 481

EXAMPLE 122 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(quinol-2-ylamino)propanoic acid

2-Aminoquinoline gave the title compound (4.3 mg)

HPLC-MS Retention time 2.20 min; MH⁺ 481.

EXAMPLE 123 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(quinol-3-ylamino)propanoic acid

3-Aminoquinoline gave the title compound (5.1 mg)

HPLC-MS Retention time 2.22 min; MH⁺481.

EXAMPLE 124 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-chloro-2-(methylthio)pyrimidin-6-yl amino]propanoic acid

6-Amino-4-chloro-2-(methylthio)pyrimidine gave the title compound (1.4mg)

HPLC-MS Retention time 2.63 min; MH⁺ 512.

EXAMPLE 125 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3,5-dichloro-2,6-difluoropyrid-4-ylamino)propanoic acid

4-Amino-3,5-dichloro-2,6-difluoropyridine gave the title compound (1.1 mg)

HPLC-MS Retention time 2.81 min; MH⁺ 535.

EXAMPLE 126 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethylpyrid-2-ylamino)propanoic acid

2-Amino-4,6-dimethylpyridine gave the title compound (3.9 mg)

HPLC-MS Retention time 2.11 min; MH⁺ 459.

EXAMPLE 127 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethoxypyrimidin-2-ylamino) propanoic acid

2-Amino-4,6-dimethoxypyrimidine gave the title compound (3.0 mg)

HPLC-MS Retention time 2.56 min; MH⁺ 492.

EXAMPLE 128 3-[4-(3,5-Dichlorolyrid-4-ylcarboxamido)phenyl]-2-(2-methylpyrid-4-ylamino)propanoic acid

4-Amino-2-methylpyridine gave the title compound (1.3 mg)

HPLC-MS Retention time 2.09 min; MH⁺ 445.

EXAMPLE 129 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-chloropyrid-3-ylamino)propanoic acid

3-Amino-6-chloropyridine gave the title compound (2.7 mg)

HPLC-MS Retention time 2.52 min; MH⁺ 465.

EXAMPLE 130 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-bromopyrid-2-ylamino)propanoic acid

2-Amino-5-bromo-2-pyridine gave the title compound (2.6 mg)

HPLC-MS Retention time 2.60 min; MH⁺ 510.

EXAMPLE 131 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2,6-dichloropyrid-4-ylamino)pronanoic acid

4-Amino-2,6-dichloropyridine gave the title compound (1.6 mg)

HPLC-MS Retention time 2.62 min; MH⁺ 499.

EXAMPLE 132 3-[4-(3,5-Dichlorolpyrid-4-ylcarboxamido) phenyl]-2-(3,5-dibromopyrid-2-ylamino)propanoic acid

2-Amino-3,5-dibromopyridine gave the title compound (0.2 mg)

HPLC-MS Retention time 2.83 min; MH⁺ 589.

EXAMPLE 133 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethylpyrimidin-2-ylamino)propanoic acid

2-Amino-4,6-dimethylpyrimidine gave the title compound (2.7 mg)

HPLC-MS Retention time 2.23 min; MH⁺ 460.

EXAMPLE 134 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-ethyl-6-methylpyrid-2-ylamino)propanoic acid

2-Amino-3-ethyl-6-methylpyridine gave the title compound (1.3 mg)

HPLC-MS Retention time 2.23 min; MH⁺ 473.

EXAMPLE 135 3-[4-(3,5-Dichlorolpyrid-4-ylcarboxamido)phenyl]-2-(4-ethylpyrid-2-ylamino)propanoic acid

2-Amino-4-ethylpyridine gave the title compound (0.8 mg)

HPLC-MS Retention time 2.14 min; MH⁺ 459.

EXAMPLE 136 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-ethylpyrid-2-ylamino)propanoic acid

2-Amino-6-ethylpyridine gave the title compound (2.4 mg)

HPLC-MS Retention time 2.14 min; MH⁺ 459.

EXAMPLE 137 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2,5-dichloropyrid-3-ylamino)propanoic acid

3-Amino-2,5-dichloropyridine gave the title compound (1.0 mg)

HPLC-MS Retention time 2.68 min; MH⁺ 501.

EXAMPLE 138 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-trifluoromethylpyrimidin-2-ylamino)propanoic acid

2-Amino-4-trifluoromethylpyrimidine gave the title compound (1.2 mg)

HPLC-MS Retention time 2.62 min; MH⁺ 500.

EXAMPLE 139 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-bromopyrimidin-2-ylamino)propanoic acid

2-Amino-5-bromopyrimidine gave the title compound (0.6 mg)

HPLC-MS Retention time 2.56 min; MH⁺ 511.

EXAMPLE 140 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-chloropyrid-3-ylamino)propanoic acid

3-Amino-2-chloropyridine gave the title compound (2.5 mg)

HPLC-MS Retention time 2.52 min; MH⁺ 465.

EXAMPLE 141 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-trifluoromethyl-6-methylpyrimidin-2-ylamino)propanoic acid

2-Amino-4-trifluoromethyl-6-methylpyrimidine gave the title compound (3.1 mg)

HPLC-MS Retention time 2.65 min; MH⁺ 514.

EXAMPLE 142 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dichloro-2-methylpyrimidin-5-ylamino)propanoic acid 5-Amino-4,6-dichloro-2-methylpyrimidine gave the title compound (1.7 mg)

HPLC-MS Retention time 2.55 min; MH⁺ 516.

EXAMPLE 143

3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6dimethoxypyrimidin-5-ylamino)propanoic acid

5-Amino-4,6-Dimethoxypyrimidine gave the title compound (0.9 mg)

HPLC-MS Retention time 2.43 min; MH⁺ 492.

EXAMPLE 144 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-benzyloxypyrid-2-ylamino)propanoic acid

2-Amino-3-benzyloxypyridine gave the title compound (2.8 mg)

HPLC-MS Retention time 2.33 min; MH⁺ 537.

EXAMPLE 145 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-(5-chloropyrid-2-yloxy)phenylamino]propanoic acid

4-(5-Chloropyrid-2-yloxy)aniline gave the title compound (1.7 mg)

HPLC-MS Retention time 2.73 min; MH⁺ 557.

EXAMPLE 146 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-chloro-5-phenylpyrid-6-ylamino)propanoic acid

6-Amino-2-chloro-5-phenylpyridine gave the title compound (0.5 mg)

HPLC-MS Retention time 2.87 min MH⁺ 541.

EXAMPLE 147 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(1-oxidopyrid-3-ylamino)propanoic acid

3-Aminopyridine-1-oxide gave the title compound (1.1 mg)

HPLC-MS Retention time 2.16 min; MH⁺ 447.

EXAMPLE 148 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-(4-methylphenyl)pyrimidin-2-ylamino]propanoic acid

2-Amino-4-(4-methylphenyl)pyrimidine gave the title compound (2.2 mg)

HPLC-MS Retention time 2.57 min; MH⁺ 522.

EXAMPLE 149 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-(4-chlorophenyl)pyrimidin-2-ylamino]propanoic acid

2-Amino-4-(4-chlorophenyl)pyrimidine gave the title compound (0.8 mg)

HPLC-MS Retention time 2.67 min; MH⁺ 542.

EXAMPLE 150 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-chloro-6-pyrrolidinopyrimidin-2-ylamino)propanoic acid

2-Amino-4-chloro-6-pyrrolidinopyrimidine gave the title compound (3.2 mg)

HPLC-MS Retention time 2.59 min; MH⁺ 537.

EXAMPLE 151 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-(chlorodifluoromethyl)-6-methyl pyrimidin-2-ylamino)propanoic acid

2-Amino-4-(chlorodifluoromethyl)-6-methylpyrimidine gave the title compound (0.6 mg)

HPLC-MS Retention time 2.66 min; MH⁺ 532.

EXAMPLE 152 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3,5-difluorophenylamino)propanoic acid

3,5-Difluoroaniline gave the title compound (1 mg)

HPLC-MS Retention 2.67 min; MH⁺ 466.

EXAMPLE 153 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2,4,6-trimethylphenylamino)propanoic acid

2,4,6-Trimethylaniline gave the title compound (4 mg)

HPLC-MS Retention 2.77 min; MH⁺ 472.

EXAMPLE 154 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2,6-diethylphenylamino)propanoic acid

2,6-Diethylaniline gave the title compound (6 mg)

HPLC-MS Retention 2.85 min; MH⁺ 486.

EXAMPLES 155 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-(trifluoromethyl)phenylamino)propanoic acid

3-(Trifluoromethyl)aniline gave the title compound (3 mg)

HPLC-MS Retention 2 74 min; MH⁺ 498.

EXAMPLE 156 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-propylphenylamino)propanoic acid

2-Propylaniline gave the title compound (2 mg)

HPLC-MS Retention 2.80 min; MH⁺ 472.

EXAMPLE 157 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-ethylphenylamino)propanoic acid

4-Ethylaniline gave the title compound (2 mg)

HPLC-MS Retention 2.72 min; MH⁺ 458.

EXAMPLE 158 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3,4,5-trichlorophenylamino)propanoic acid

3,4,5-Trichloroaniline gave the title compound (1 mg)

HPLC-MS Retention 2.86 min; MH⁺ 532.

EXAMPLE 159 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3,4,5-trifluorophenylamino)propanoic acid

3,4,5-Trifluoroaniline gave the title compound (3 mg)

HPLC-MS Retention 2.70 min; MH⁺ 484.

EXAMPLE 160 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-benzylphenylamino)propanoic acid

2-Benzylaniline gave the title compound (1 mg)

HPLC-MS Retention 2.84 min; MH⁺ 520.

EXAMPLE 161 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3,5-bis(trifluoromethyl)phenylamino)propanoic acid

3,5-Bis(trifluoromethyl)aniline gave the title compound (1 mg)

HPLC-MS Retention 2.87 min; MH⁺ 566.

EXAMPLE 162 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-isopropylphenylamino)propanoic acid

4-Isopropylaniline gave the title compound (2 mg)

HPLC-MS Retention 2 80 min; MH⁺ 472.

EXAMPLE 163 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-trifluoromethoxyphenylamino)propanoic acid

3-Trifluoromethoxyaniline gave the title compound (4 mg)

HPLC-MS Retention 2.76 min; MH⁺ 514.

EXAMPLE 164 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2-fluoro-5-(trifluoromethyl)phenylamino)propanoic acid

2-Fluoro-5-(trifluoromethyl)aniline gave the title compound (4 mg)

HPLC-MS Retention 2.75 min; MH⁺ 516.

EXAMPLE 165 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-chloro-4-fluorophenylamino)propanoic acid

3-Chloro-4-fluoroaniline gave the title compound (6 mg)

HPLC-MS Retention 2.70 min; MH⁺ 482.

EXAMPLE 166 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-nitrophenylamino)propanoic acid

3-Nitroaniline gave the title compound (2 mg)

HPLC-MS 2.62 min; MH⁺ 475.

EXAMPLE 167 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(2,3,5,6-tetrafluorophenylamino)propanoic acid

2,3,5,6-tetrafluoroaniline gave the title compound (1 mg)

HPLC-MS Retention 2.72 min; MH⁺ 502.

EXAMPLE 168 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-chlorophenylamino)propanoic acid

3-Chloroaniline gave the title compound (1 mg)

HPLC-MS Retention 2.70 min; MH⁺ 464.

The following assays can be used to demonstrate the potency and selectivity of the compounds according to the invention. In each of these assays an IC₅₀ value was determined for each test compound and represents the concentration of compound necessary to achieve 50% inhibition of cell adhesion where 100%=adhesion assessed in the absence of the test compound and 0%=absorbance in wells that did not receive cells.

α₄β₁ Integrin-dependent Jurkat Cell Adhesion to VCAM-Ig

96 well NUNC plates were coated with F(ab)₂ fragment goat anti-human IgG Fcγ-specific antibody [Jackson Immuno Research 109-006-098: 100 μl at 2 μg/ml in 0.1M NaHCO₃, pH 8.4], overnight at 4°. The plates were washed (3×) in phosphate-buffered saline (PBS) and then blocked for 1 h in PBS/1% BSA at room temperature on a rocking platform. After washing (3× in PBS) 9 ng/ml of purified 2d VCAM-lg diluted in PBS/1% BSA was added and the plates left for 60 minutes at room temperature on a rocking platform. The plates were washed (3× in PBS) and the assay then performed at 37° for 30 min in a total volume of 200 μl containing 2.5×10⁵ Jurkat cells in the presence or absence of titrated test compounds.

Each plate was washed (2×) with medium and the adherent cells were fixed with 100μl methanol for 10 minutes followed by another wash. 100μl 0.25% Rose Bengal (Sigma R4507) in PBS was added for 5 minutes at room temperature and the plates washed (3×) in PBS. 100μl 50% (v/v) ethanol in PBS was added and the plates left for 60 min after which the absorbance (570 nm) was measured.

α4β₇ Integrin-dependent JY Cell Adhesion to MAdCAM-Ig

This assay was performed in the same manner as the α₄β₁ assay except that MAdCAM-Ig (150 ng/ml) was used in place of 2d VCAM-Ig and a sub-line of the β-lympho blastoid cell-line JY was used in place of Jurkat cells. The IC₅₀ value for each test compound was determined as described in the α₄β1 integrin assay.

α₅β₁ Intecirin-dependent K562 Cell Adhesion to Fibronectin

96 well tissue culture plates were coated with human plasma fibronectin (Sigma F0895) at 5 μg/ml in phosphate-buffered saline (PBS) for 2 hr at 37° C. The plates were washed (3× in PBS) and then blocked for 1 h in 100μl PBS/1% BSA at room temperature on a rocking platform. The blocked plates were washed (3× in PBS) and the assay then performed at 37° C. in a total volume of 200 μp containing 2.5×10⁵ K562 cells, phorbol-12-myristate-13-acetate at 10 ng/ml, and in the presence or absence of titrated test compounds. Incubation time was 30 minutes. Each plate was fixed and stained as described in the α₄β₁ assay above.

α_(m)β₂-Dependent Human Polymorphonuclear Neutrophils Adhesion to Plastic

96 well tissue culture plates were coated with RPMI 1640/10% FCS for 2 h at 37° C. 2×10⁵ freshly isolated human venous polymorphonuclear neutrophils (PMN) were added to the wells in a total volume of 200 μl in the presence of 10 ng/ml phorbol-12-myristate-13-acetate, and in the presence or absence of test compounds, and incubated for 20 min at 37° C. followed by 30 min at room temperature. The plates were washed in medium and 100 μl 0.1% (w/v) HMB (hexadecyl trimethyl ammonium bromide, Sigma H5882) in 0.05M potassium phosphate buffer, pH 6.0 added to each well. The plates were then left on a rocker at room temperature for 60 min. Endogenous peroxidase activity was then assessed using tetramethyl benzidine (TMB) as follows: PMN lysate samples mixed with 0.22% H₂O₂ (Sigma) and 50μg/ml TMB (Boehringer Mannheim) in 0.1M sodium acetate/citrate buffer, pH 6.0 and absorbance measured at 630 nm.

αIIb/β₃-dependent Human Platelet Aggregation

Human platelet aggregation was assessed using impedance aggregation on the Chronolog Whole Blood Lumiaggregometer. Human platelet-rich plasma (PRP) was obtained by spinning fresh human venous blood anticoagulated with 0.38% (v/v) tri-sodium citrate at 220×g for 10 min and diluted to a cell density of 6×10⁸/ml in autologous plasma. Cuvettes contained equal volumes of PRP and filtered Tyrode's buffer (g/liter: NaCl 8.0; MgCl₂.H₂O 0.427; CaCl₂ 0.2; KCl 0.2;1 D-glucose 1.0; NaHCO₃ 1.0; NaHPO₄.2H₂O 0.065). Aggregation was monitored following addition of 2.5 μM ADP (Sigma) in the presence or absence of inhibitors.

In the above assays the preferred compounds of the invention generally have IC₅₀ values in the α₄β₁ and α₄β₇ assays of 1 μM and below. In the other assays featuring α integrins of other subgroups the same compounds had IC₅₀ values of 50 μM and above thus demonstrating the potency and selectivity of their action against α₄ integrins. 

What is claimed is:
 1. A compound of formula (1)

wherein: Ar¹ is an aromatic group or a heteroaromatic group selected from phenyl, pyridyl or pyrimidinyl; R¹, R², R³, R⁴, and R⁵, which may be the same or different, are each —L²(Alk³)_(t)L³(R⁷)_(u); L¹, L² and L³, which may be the same or different, are each a covalent bond, an —O— or —S— atom, or a linker group selected from —C(O)—, —C(O)O—, —OC(O)—, —C(S)—, —S(O)—, —S(O)₂—, —N(R¹¹)—, —CON(R¹¹)—, —OC(O)N(R¹¹)—, —CSN(R¹¹)—, —N(R¹¹)CO—, —N(R¹¹)C(O)O—, —N(R¹¹)CS—, —SO₂N(R¹¹)—, —N(R¹¹)SO₂—, —N(R¹¹)CON(R¹¹)—, —N(R¹¹)CSN(R¹¹)— and —N(R¹¹)SO₂N(R¹¹)—; R⁷ is a hydrogen or halogen atom or a group selected from alkyl, —OR⁸, —SR⁸, —NR⁸R⁹, —NO₂, —CN, CO₂R⁸, SO₃H, —SO₂R⁸, —OCO₂R⁸, —CONR⁸R⁹, —OCONR⁸R⁹, —CSNR⁸R⁹, —COR⁸, —OCOR⁸, —N(R⁸)COR⁹, —N(R⁸)CSR⁹, —SO₂N(R⁸)(R⁹), —N(R⁸)SO₂R⁹, —N(R⁸)CON(R⁹)(R¹⁰), —N(R⁸)CSN(R⁹)(R¹⁰) and —N(R⁸)SO₂N(R⁹)(R¹⁰); R⁸, R⁹, R¹⁰ and R¹¹, which may be the same or different, are each a hydrogen atom or an optionally substituted alkyl group; t is zero or the integer 1; u is an integer 1, 2, or 3; Alk¹ is an optionally substituted aliphatic or heteroaliphatic chain; Alk² is a straight or branched chain alkylene chain; Alk³ is an aliphatic or heteroaliphatic chain; m is zero or the integer 1; R⁶ is a hydrogen atom or a methyl group; r is zero or the integer 1; R is a carboxylic acid group (—CO₂H) or an ester or amide derivative thereof; R^(a) is a hydrogen atom or a methyl group; g is zero or the integer 1; Ar² is an optionally substituted aromatic group or an optionally substituted C₁₋₉ monocyclic or bicyclic heteroaromatic group containing one to four heteroatoms selected from oxygen, sulfur and nitrogen atoms; and the salts, solvates, hydrates and N-oxides thereof; with the provisos that when L¹ is —O—, then r is zero; and when Ar¹ is a phenyl group, L¹ is —OC(O)—, r is zero, each of R¹, R², R³, R⁴, R⁵, R⁶, and R^(a) is a hydrogen atom, m is the integer 1, Alk² is a CH₂ group, R is a carboxylic acid ethyl ester, and g is zero, Ar² is other than a benthiazole group.
 2. A compound according to claim 1 in which R is a —CO₂H group.
 3. A compound according to claim 1 in which Alk² is a —CH₂— chain and m is the integer
 1. 4. A compound according to claim 1 in which R⁶ and R^(a) is each a hydrogen atom.
 5. A compound according to claim 1 in which Ar¹ is a phenyl, pyridyl or pyrimidyl group, wherein R¹ and R² is each a halogen atom, alkyl or haloalkyl group or alkoxy or haloalkoxy group and R³ is hydrogen.
 6. A compound according to claim 1 in which (Alk¹)_(r)L¹ is a —CONH— group.
 7. A compound according to claim 1 in which Ar² is an optionally substituted phenyl, pyridyl, pyrimidyl, pyridazinyl or 1,3,5-triazinyl group.
 8. A compound which is: S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylsulphinylpyrimidin-4-ylamino)propanoic acid; S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[3,5-dichloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methoxy-2-methylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methoxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-(2-hydroxyethylamino)-1,3,5-triazin-2-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-(4-carboxypiperidinyl)-1,3,5-triazin-2-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-piperazinyl-1,3,5-triazin-2-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methyl-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-benzylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-carboxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-chloropyridazin-3-yl-amino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylpyrazin-2-ylamino)propanoic acid; 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylbenzeneamino)propanoic acid; 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphonylpyridin-2-ylamino)propanoic acid; 3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-propylsulphonylpyridin-2-ylamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-trifluoromethylpyrimidin-2-ylamino)propanoic acid; S-3-[4-(3,5-Dichloro-1-oxidopyridino-4-ylcarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylaminoamino)propanoic acid; S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-methoxy-6-(3-hydroxypropylamino)1,3,5-triazin-2-ylamino]propanoic acid; and the salts, solvates, hydrates and N-oxides thereof.
 9. A pharmaceutical composition comprising a compound according to claim 1 together with one or more pharmaceutically acceptable carriers, excipients or diluents.
 10. A compound of formula (2)

wherein: R¹, R², R⁴, and R⁵, which may be the same or different, are each —L²(Alk³)_(t)L³(R⁷)_(u); L¹, L² and L³, which may be the same or different, are each a covalent bond, an —O— or —S— atom, or a linker group selected from —C(O)—, —C(O)O—, —OC(O)—, —C(S)—, —S(O)—, —S(O)₂—, —N(R¹¹)—, —CON(R¹¹)—, —OC(O)N(R¹¹)—, —CSN(R¹¹)—, —N(R¹¹)CO—, —N(R¹¹)C(O)O—, —N(R¹¹)CS—, —SO₂N(R¹¹)—, —N(R¹¹)SO₂—, —N(R¹¹)CON(R¹¹)—, —N(R¹¹)CSN(R¹¹)— and —N(R¹¹)SO₂N(R¹¹)—; R⁷ is a hydrogen or halogen atom or a group selected from alkyl, —OR⁸, —SR⁸, —NR⁸R⁹, —NO₂, —CN, CO₂R⁸, SO₃H, —SO₂R⁸, —OCO₂R⁸, —CONR⁸R⁹, —OCONR⁸R⁹, —CSNR⁸R⁹, —COR⁸, —OCOR⁸, —N(R⁸)COR⁹, —N(R⁸)CSR⁹, —SO₂N(R⁸)(R⁹), —N(R⁸)SO₂R⁹, —N(R⁸)CON(R⁹)(R¹⁰), —N(R⁸)CSN(R⁹)(R¹⁰) and —N(R⁸)SO₂N(R⁹)(R¹⁰); R⁸, R⁹, R¹⁰ and R¹¹, which may be the same or different, are each a hydrogen atom or an optionally substituted alkyl group; t is zero or the integer 1; u is an integer 1, 2, or 3; Alk¹ is an optionally substituted aliphatic or heteroaliphatic chain; Alk² is a straight or branched chain alkylene chain; Alk³ is an aliphatic or heteroaliphatic chain; m is zero or the integer 1; R⁶ is a hydrogen atom or a methyl group; r is zero or the integer 1; R is a carboxylic acid group (—CO₂H) or an ester or amide derivative thereof; R^(a) is a hydrogen atom or a methyl group; g is zero or the integer 1; Ar² is an optionally substituted aromatic group or an optionally substituted heteroaromatic group containing one to four heteroatoms selected from oxygen, sulfur and nitrogen atoms; and the salts, solvates, hydrates and N-oxides thereof; with the provisos that when one of R¹ and R² is a hydrogen atom, then the other of R¹ and R² is other than a hydrogen atom, and when L¹ is —O—, then r is zero.
 11. A compound according to claim 10 wherein: R¹ and R², which may be the same or different, are each a halogen atom or a C₁₋₆alkyl, haloC₁₋₆alkyl or haloC₁₋₆alkoxy group; R is a carboxylic acid group (—CO₂H); (Alk¹)_(r)L¹ is —CH₂O— or —CON(R¹¹)—; Alk² is —CH₂—; R⁴ and R⁵, which may be the same or different, are each a hydrogen or halogen atom or an alkyl, alkoxy, hydroxy, nitro, cyano or —NR⁸R⁹ group; and R⁶ and R^(a) are each a hydrogen atom.
 12. A pharmaceutical composition comprising a compound according to claim 10 together with one or more pharmaceutically acceptable carriers, excipients or diluents. 